I'm a Palm user, and think it's a very good fit for the PDA & Smartphone markets.

Here are a few of the more interesting models:

Just a basic PDA:
The entry level Clies are good here (e.g. TJ25 at about $160). Their cases are nicer than the entry PalmOnes, and I've been very happy with my old T610.
Or consider PDA/Cellphone combo (e.g. Treo 600 or the compact Samsung iSPH-500), although I think most smartphones are too big.

PDA + games
The Tapwave an interesting option, with 32M RAM for $300 and 128M RAM for $400, full Palm OS5 functionality, hardware graphics accelerator, and analog joystick.

Stop getting lost:
Garmin iQue-3600 (about $450) with GPS and software, Palm OS5. My friend has one of these, and loves it. Batteries do run down fast, but it is fast, the software is good, and it has a 320x480 display. I might be getting one later this year.

Some of the PDA sites are:
[link|http://www.PalmInfoCenter.com|http://www.PalmInfoCenter.com]
[link|http://www.BrightHand.com|http://www.BrightHand.com]
[link|http://www.bargainPDA.com|http://www.bargainPDA.com]