I've had a Blackberry since they were first released about 2.5 years ago - I'm on my 3rd one right now.
If you're looking for a simple business communication tool, it can't be beat. Wireless e-mail and calendaring are it's strong points. It will do tasks, address books, etc. fine, and has very limited Internet browsing capabilities.
A PDA it's not, but if what you need is simply to stay in touch, it's an excellent tool. Nice, large display with plenty of real estate, good keyboard, and simple interface are definite pluses. Lack of flexibility (ONE game might be nice, even something as simple as MineSweeper), large physical footprint on the belt and lack of any IM features are cons.
There's a lot people around my company that have taken to calling them "crackberries". They are mostly the people that don't have them, however - They just see others madly typing on them in meetings, etc.
My favorite thing, however, is that it's my "ultimate hookey device." I don't have to be in the office to be able to read e-mails and response to them promptly, as necessary. Especially handy when taking a 2-hour lunch at Gameworks. *grin*
Edit: Another con - On my "Blueberry", the phone sucked. Crappy reception and it was very uncomfortable to use. I cancelled it in favor of my old separate cell phone.
- G