I've been a fan of the PalmOne (nee Handspring) Treo since the very first model was released back in... well, a long time ago. In fact, I wanted one *before* they came out. I endured the ridicule of my coworkers for having a Star Trek phone (see here) After more than a year, I upgraded to the 600, and last November, the 650.
Along the way, I found a really awesome email program called Chattermail. It uses the IDLE functionality of Exchange's IMAP implementation to maintain a connection with the server 24/7. Because GSM data sessions can be interrupted by incoming voice calls, I remain connected to my inbox all day long, no matter where I'm at.
My PPC friends are still trying to catch up - I spent time today with a coworker, trying to get his brand new HTC Apache running w/ push email, only to find that the needed software hadn't been released by Verizon yet. Hang in there guys, you'll catch up some time!
I'm travelling to Florida for a couple of days - debating whether to bring the laptop or not. Now if I could only attach a full-sized keyboard to my phone...