The smallest Palm PDA
The Fossil Wrist PDA smartwatch - the model 2.0 from about 2004.
The Fossil (also sold as the Abacus) Wrist PDA was actually a full-featured but miniaturised version of older Palm pocket computer. It even has the same screen resolution.
It's passive BW display seemed to be obsolete when it was introduced (the comparable Palm PDA computers - the comparable Palm III, V and the m500 lines were from 1998-2000.
Its main problems are moderate battery life (1-3 days) and its weight (over 100 grams - a comparable PDA was about 180 grams). They also aren't water resistant. The 1" screen is also not optimal for many users (there is a mode with bigger icons - only 4 can be shown - but the rest of probrams has still the same size).
Anyway, it offers to have a complete PALM-compatible PDA on the wrist. It supports Graffiti data input, most of Palm OS applications. The stylus is included, of course.
Obviously, there are some limitations: unavailability of some standard hardware and software buttons - so one cannot control some programs and cannot even open the program menu - it's a case of the CSpotRun.
But there are rich (for it's time) connection options: miniUSB connector (both for charging and data transfer) and infrared port - thus one can exchange data (and even applications!) with other Palm devices (and not obly with them) without any trouble.
I have got this one for a cheap but is is a bit weared and the Back button is damaged (so it is impossible to switch programs...).