Yes, I do, and I admit that it's really nice to always have e-mail access.
I mainly use the Blackberry for phone calls, checking my calendar (which syncs up to my work calendar), and e-mails. Occasionally I'll check the web for something, and I use the calculator a fair bit too. Mine doesn't have GPS on it (which would be a nice feature!). Blackberries also have a "Blackberry Messenger" application which is sort of like MSN Messenger, an instant messaging program. It's great for the office.