I recently upgraded my cell phone to the Cingular 8125. This is a Mobile Windows Pocket PC enabled phone. It has a small slide out keyboard and a touch screen.
It took me a little while to get it sync'd with Outlook 2003, but eventually (after turning on USB support on the phone) I know have all of my contacts, calendar and tasks sync'd up.
I'm using the XpressMail service from Cingular right now to send me mail. I have the XpressMail client running on my desktop in the office. It will sync my email and calendar live.
I just ordered a dashboard mount kit for my car and a GPS add on. I'll let you know more later.