I took the plunge and treated myself to an AT&T Tilt, aka HTC8925. It's a Smart Phone that runs Windows Mobile 6. I'm still on the early part of the learning curve, but for what it has available, I think I have quite a ways to go before I completely utilize this thing to the best of its ability.
First things first, download CodeWallet, Google Maps, and Microsoft Live. Anything else? Maybe an OpenSource GPS client.
I'll update as necessary.
(UPDATE: No need for a GPS client with Google Maps installed. GM provides a "Use GPS" feature that is more precise than their cell-phone-tower triangulation method. I can be on a call to my wife, who may be jonesin' for some sushi... use GM w/ GPS to determine where I am, and then search on SUSHI and POP... up comes Sushi Samba and some others. Sweet Nigiri-lovin'.
With GM/GPS, no "drive-by-turn" instructions with that all-too-familiar voice telling me to make an immediate u-turn when possible.
GM/GPS might make for a good way to search on business/franchise opportunities... looking for the gaps
I also added the WiFiFoFum application for nerdy war-driving... just turn-on the wifi, and GPS, and watch the open WiFi-spots display to my amazement. If you have WiFi at home... turn-off broadcast SSID, please.)