ubertwitter is a twitter client specially designed for blackberry phones.
Uber twitter supports multiple accounts, come with an inbuilt url shortner from Bit.ly and it can shrink your tweets to fit into 40 characters.

Blackberry users have a huge number of application to tweet from like twitterberry and ubertwitter. Many people prefer ubertwitter for blackberry.
Replying to tweets and direct messaging is fun from uber twitter. Posting videos and photos is a lot faster and you can track twitters popular trending topics . All this for free albeit you have some adds to bear in the free version ! You have different setting for different account if you set up multiple account cool aint it
This application is a must have for blackberry users who are addicted to twitter I recommend you to try it .
Beta-7 has been released! | ÜberTwitter