When you're on the go, sometimes even the smallest laptop can weigh you down. Handheld computers, which offer more capabilities every year, might seem more appealing. We tried out four of the latest Mac-compatible handhelds that run Palm OS: Handspring's Treo 300, Palm Computing's Tungsten T and Zire, and Sony's Clie PEG-NX70V.

All four handhelds have the basics. Each allows you to use a relatively easy-to-learn handwriting scheme called Graffiti to enter data, beam data to other handhelds via infrared ports, and recharge the battery with AC power.

But that's where the similarities end. The Zire is a very basic PDA for the user who wants what amounts to an electronic address book and calendar; the Tungsten T is a PDA with a color screen, Bluetooth connectivity, and other high-end features; the Treo adds a cell phone; and the Clie is both a PDA and a digital camera. Each of these high-quality handhelds will surely meet the needs of specific types of users, but our highest overall recommendations go to the Tungsten T and the Zire, for their quality and design.

A PDA Named Zire

If you're a busy person who wants to store contact information, notes, and calendar entries in a light, portable, no-frills PDA, the Zire was built with you in mind. It comes with 2MB of memory for storage, and unlike the more expensive handhelds, it doesn't have slots for adding storage cards, or ports that allow it to connect to a variety of peripherals. So if you like the idea of adding cards for backup or applications, or of connecting to gear such as the Palm Portable Keyboard, the Zire will seem limiting.

The Zire is about 3 inches wide, 0.5-inch thick, and 4.5 inches tall, making it just a bit bigger than an iPod. But the 3.8-ounce Zire is noticeably lighter than the 10GB iPod, and a simple rubber flap covers and protects its screen. With its small monochrome display, the Zire is not for people who have trouble reading small text. Also, the screen isn't backlit -- a standard feature of more-expensive monochrome and color handhelds -- so when dusk begins to fall, it's time to put the Zire away.

People familiar with earlier Palm models will find their way around easily. Below the viewable portion of the screen is a touch-sensitive section for writing Graffiti or tapping on built-in icons that let users issue commands or jump to applications; below that area are up and down buttons, a Datebook button, and an Address Book button.

Most PDAs require cradles to exchange data with the Mac via USB, but the Zire connects with a simple cable. If you're on the road, you might appreciate this -- however, PDAs that use proper cradles have a different kind of advantage: the cradle-connection port also allows them to connect with the aforementioned Palm Portable Keyboard, business-card scanners, MIDI sound modules (which turn your PDA into a synthesizer), and many other peripherals. If you're trying to simplify your life and not add more gadgets to it, though, the unadorned, self-contained Zire may be just the ticket.

Gleaming Tungsten

If the Zire defines the humble side of Palm Computing's PDA line, the Tungsten T, a color PDA with stereo sound, epitomizes its extravagant side. This device is designed for people who want entertainment, expandability, and flexibility in a PDA.

The Tungsten T is eminently portable -- it's about the same size as an iPod and a tad lighter. It has a unique design: pull on the bottom of the PDA's front panel, and it expands to reveal a Graffiti-writing area. The device's clip-on cover can be a bit of a pain -- when you want to use the Tungsten T, you have to unsnap the cover and then snap it to the back before you can get to work.

The Tungsten T ships with 16MB of storage, but you can add more space via its Secure Digital (SD) card slot. SD cards are about the size of a postage stamp, and you can buy cards capable of storing as much as 256MB of data (SanDisk, at www.sandisk.com, makes a 32MB SD card for $35).

Because the Tungsten T includes stereo-sound capabilities, you can use it as an MP3 player, but you'll need additional software, as well as enough storage space for your music. We tried out the $16 AeroPlayer, from Aerodrome Software (www.aerodromesw.com), and the sound from the Tungsten T was rich, full, clear, and strong.

The Tungsten T has an incredibly sharp, bright 320-by-320-pixel color screen. The colors are rich, and the displayed text is easy to read. Best of all, the Tungsten T's screen remains very sharp and legible in bright sunlight.

For navigation, the Tungsten T provides a five-way thumb switch and four application buttons. In addition, a small button on the left calls up preinstalled software that lets users record voice memos.

The Tungsten T can connect to a Mac via a USB cradle, but its real perk is connecting via Bluetooth without requiring that users purchase additional hardware. It gets better: if you have a Bluetooth-enabled mobile phone, you can not only share contact information between your Tungsten T and the phone, but also use the phone to set up a wireless Web connection for your PDA. If you want a PDA that can easily speak with the other peripherals in your digital hub, you'll find that the Tungsten T can reach out in many ways.

Treo for the Road

For users who don't want to juggle a handheld and a mobile phone, the Handspring Treo 300 offers a cool two-in-one option.

The Treo 300 is about the same size as the Tungsten T, and it's just a bit heavier, at 5.7 ounces. It ships with a USB cable rather than a cradle for connecting to a Mac, so it's easy to transport. You can order a cradle for the Treo, and its cradle-connection port theoretically allows it to connect with peripherals. However, the connector is nonstandard, and as of press time, no folding keyboards or other such peripherals had been designed for it. The Treo ships with 16MB of storage, and it doesn't provide any expansion slots for additional memory.

The Treo has a 160-by-160-pixel screen, and it supports fewer colors than the Tungsten T, so images appear a bit coarser. This is acceptable, but in bright sunlight, the Treo's screen was nearly impossible to read, even after we had adjusted the contrast and brightness.

Along with the usual application and up and down buttons, the Treo has a clickable, scrolling thumb wheel. One addition we weren't expecting is the Treo's keyboard, reminiscent of Research In Motion's Black-Berry pagers'. The keyboard sits below the screen, and you push the tiny oval buttons with your thumbs to type. The Treo has no Graffiti-writing area, which disappointed us at first. Fortunately for those who prefer Graffiti, Handspring, in partnership with CIC, offers RecoEcho, a free utility that lets you write Graf-fiti anywhere on screen. It worked flawlessly, and it greatly enhanced our Treo experience.

The Treo uses a Sprint PCS 3G network for its wireless phone service, which provided better coverage than a regular Sprint PCS network in some informal tests we made in the same service area. Voices came through more clearly and signals didn't break up as easily. Also, you can use your Treo's applications while you talk on the phone.

Best of all, the Treo provides wireless Web surfing. It downloads text and images relatively quickly, but don't expect broadband speeds. A simple page such as Google's main screen (www .google.com) takes about two seconds to appear, but Apple's page (www.apple.com) takes a full two minutes.

The Treo 300 is a very useful device for people who don't want to carry around both a PDA and a cell phone, but the screen's poor performance in bright sunlight makes it a little awkward to use.

The Multitalented Clie

What if you wanted a PDA that was not just a PDA or a PDA with a phone, but an MP3 player and a digital camera? You'd have the Sony Clie PEG-NX70V. This handheld is the biggest and heaviest of the bunch, standing a full 5.5 inches high and weighing 7.5 ounces. Like the other higher-end handhelds we tried out, the Clie has a color screen and ships with 16MB of storage.

The Clie gives you multiple options for extending storage and memory. It can take both CompactFlash cards and Memory Sticks, and because it uses a cradle, it's also got a connector on the bottom, which allows you to connect a folding keyboard, as you can with the Tungsten T. And you can mount Memory Sticks right on your Mac's desktop, which allows you to drag files directly to the Clie, turning it into a hard drive.

The Clie requires a $30 third-party application, Mark/Space's The Missing Sync (www.markspace.com), to connect to your Mac. This program, available for both OS 9 and OS X, worked without any problems.

The Clie's screen is on its lid, which might sound unusual; indeed, we found it pretty awkward to write Graffiti on the lid with the base of the PDA dangling beneath it, especially considering the Clie's weight. But the lid can swivel completely around to face out, so when you close it you can hold the Clie comfortably in one hand as you enter text. The Clie has another unique design feature: the Graffiti area is actually part of the display, so you can hide it; this gives you a screen with roughly one-third more real estate (320 by 480 pixels) than the screens of the other PDAs we looked at provide. Like the Tungsten T's, the Clie's screen is very easy on the eyes, but fonts are a bit lighter, and it doesn't hold up quite as well in bright sunlight as the Tungsten T.

Like the Treo, the Clie has its own keyboard, which sits at the base of the handheld with the application and up and down buttons; it also has a scrolling, clickable thumb wheel for navigation.

One of the coolest things about the Clie is the digital camera cleverly concealed inside the lid's hinge. The camera works quite well for its size: it can take pictures at 640-by-480-pixel resolution and record small 2KB movies with sound that run for several minutes. The camera won't give you the greatest image quality, but the colors should be just fine for a gadget-loving amateur videographer.

As if its digital camera functionality weren't enough, the Clie also works as an MP3 player. It comes preloaded with software for playing MP3s, and Sony even throws in a pair of headphones and a remote. When we listened to the same tune side-by-side on the Tungsten T and the Clie, no obvious victor emerged. However, one advantage of the Clie is that if you connect it to your Mac, iTunes can play your MP3s from the Clie directly.

Macworld's Buying Advice

These four Palm OS-based handhelds represent a wide sampling of the major vendors' offerings; your specific needs and whether you can live with a PDA's minor drawbacks are the main factors when choosing such a device. That said, the solid design of the two Palms -- the Zire and the Tungsten T -- pleased us most. The Zire is perfect if you want a bare-bones PDA; the Tungsten T is a good choice for all-around options and expandability; the Handspring Treo 300 will do the trick for people who want to consolidate the devices they carry around; and the Sony Clie PEG-NX70V is an excellent -- though expensive -- purchase if you want to record and store small, low-resolution photos or movies on the go.