I have the HTC Touch, which I use for both business and personal use. Running on WM 6, it gracefully integrates with my company's Outlook Exchange email system, as well as my personal accounts (yes multiple) with Gmail (2 accts), Yahoo, and other proprietary IMAP & POP accounts. It gives me great flexibility for staying in touch and working on the road. It hooks up to my laptop when I'm on the road and serves as a decent modem (even 3G in some places).
I would suggest getting the Spb Mobile Shell to complement an already good interface.
