I did it this past week - I got myself a Blackberry. I was due for a contract renewal on my cell phone, and I'd been wanting to combine at least two of the electronic gadgets I carry around all the time - my phone and my calendar/address book. And after hearing about my options, the Blackberry made the most sense. The first few days with it were frustrating as hell, but once I figured out how to stop the things that were annoying it's been a piece of cake.
I remember hearing stories on the radio about people who were so attached to their "Crackberry" that their families had to do an intervention of sorts to get them to reconnect on a personal level with their own children. After less than a week with mine, I can see how that could happen. Not that I feel like I'm in danger of becoming one of those people, mind you, but if my job were in a a high-pressure field and my email account came through my phone I'd never leave work at work. Of course, one wonders if those people are the same ones who, before the Blackberry, stayed at work until the wee hours and still never saw their kids.
New toys are always fun when they're new. The phone I just upgraded from was a great little gadget when I first got it two years ago. We'll see how long it takes me to grow accustomed to the Blackberry.