Let the resident wardriving masta lead the way here
I do this with my laptop all the time. Basically your just scanning for open wireless access points. A review of how 802.11b works couldn't hurt. Hours and hours of endless entertainment.
I'm not sure what kind of software you can run on your palm, but if you can load "netstumbler" and run it then I highly reccomend it.
Let me know if you have any specific questions.