i have one too, ipaq3850, you can use this thing as navigation system (tomtom is THE BEST software), play mp3s, record voices and use it as spy recorder, use it as remote control for all your tvs, cars (to open or close doors) and so on... the best thing, you can play games or check your stats in your bed ;)... i love it, check some cool ppc sites to download games, usefull software or something.
Here are few links:
http://www.pocket.at/guide/shops1.htm