I got the Touch just as a PDA, not wanting to replace my phone or pay the extra charges. The Touch is a superb PDA. Go to the iTunes store ("apps" in the Touch) and look at the applications and podcasts. Almost all of those for the iPhone work on the Touch, although you do have to be connected via WiFi rather than anytime, anywhere. Recommended: Stanza & eReader for reading books. Urbanspoon, Speedtest, and GoogleEarth when you are on Wifi. FlightControl (about $1), Mighty Good Games' free Sudoku, eSleepLite. Of course, the built-in calendar (syncs with iCal), contacts (syncs with Address Book),music, podcasts (video and audio). There are many, many others.
twizzard