Some modern designs incorporate calculators, GPS and Bluetooth technology or have heart-rate monitoring capabilities.
A wristwatch is designed to be worn around the wrist, attached by a watch strap or other type of bracelet.
Reg Review Palm's innovative enterprise-oriented Tungsten T PDA had a good screen, but at a resolution of 320 x 320, it look rather small compared with Pocket PC devices' larger displays.
Instead, Palm chose to wait until the autumn release slot to offer a Tungsten with a bigger, i Paq-beating screen.
The result is the Tungsten T3, which not only provides a larger display - 320 x 480 now - but revamps the T series into the bargain.
Come the era of big-screen devices, however, and the slider started to seem redundant.
The Tungsten T3's 320 x 480 display is magnificent, but it defeats the object of having one if you need to open the slider every time you want to see it at its best, especially if you didn't use your PDA for data-entry.
But pressing it repeatedly now no longer cycles through the application categories but flips between the launcher and Palm One's new alternative, Favorites.
You get eight icons to the full screen, but rather than limit you to applications, you can also add URLs and documents.
Palm One was pitching the device at executives and, it reckoned, executives spend more time looking at their information than typing it in.
The slider allowed the T to become a compact data display device without sacrificing the ability to enter new information.
If you did, the slider just got in the way each time, as the Tungsten E showed.
Enter the T3's successor, the T5, and it's immediately clear Palm One has learned from both the T3 and the E, ditching the former's slider and adopting the latter's case design to produce what is not only its best PDA to date, but one that doesn't hide its glory.
It's the upgrade the T2 should have been but wasn't. Both are compact, metal-shelled devices designed for easy information look-up, but slide open to reveal a text-entry area.