Short of an app for an iPhone or iPod Touch (like ChessGenius or Deep Green), there's HIARCS for Palm hand-helds (reviewed here).
Handheld Sets / Mobile Games

Short of an app for an iPhone or iPod Touch (like ChessGenius or Deep Green), there's HIARCS for Palm hand-helds (reviewed here).
Anything decent for regular phones, or a handheld device designed for chess use only?

I've never seen anything for regular cell phones, but I haven't really looked. There's this dedicated hand-held that I've heard people talk about, but I've never seen one up close.

DeepGreene, is that thing supposed to be good? I spend a lot of time in the car and was looking for something to train me.

The Excalibur hand-held? Sorry, no idea. I've never messed with one of these units that represents the figures with LEDs. That's a turn-off for me, but maybe I'm being unfair; I've never seen one up close. Maestro makes a similar looking unit.
You mean you spend a lot of time in the car as a passenger, right?

On my cellphone, I installed Chess by Cellufun, which I find to be very well made (in addition to being free).
I only wish it had move animation (or at least highlighting), because sometimes it's hard to see where the program moved.

Anything by Mephisto by Saitek are allways good perhaps somthing from the Kasperov series might be suitable.

Chesshouse did a nice comparison table for what I guess are three of their most popular handhelds here:
http://www.chesshouse.com/Compare_Portable_Electronic_Chess_Sets_s/316.htm

I still miss my Novag Sapphire... It was a great little device, but discontinued back in the 90s for whatever reason.
It was very strong & highly configurable. (Actually, as far as the program and set-up goes, I think it was every bit as good as the Novag Obsidian I just bought late last year.) The LCD did a great job of communicating moves and even announcing "mAte n 3" and "re5n" (i.e. "I resign"), etc.
It came with a neat little magnetic analysis-style board (for non-masters of blindfold chess), but of course you could easily play on any board you wanted.
What are good, cheap chess computers that you can either download onto your mobile phone or buy a handheld for?