Be careful if you’re running TinyTwitter on your Blackberry. Once you’ve started the program, it continues to connect to the data network in the background, even if you aren’t updating. I ran into something like 20 megs/day of data usage, just because TinyTwitter was running in the background (and not even being used!).
This sounds like a pretty serious bug. Even more serious if you’re not on an unlimited data plan!