RIM has released a new version of its Twitter for BlackBerry app that allows users to connect to the BlackBerry Messenger (BBM) system. Version 3.0 of the app, released today for BlackBerry Device Software 5.0 or later, adds BBM integration, either letting users set their latest tweet as their BBM Personal Message or access contacts' Twitter accounts directly through their BBM profiles.
Twitter for BlackBerry has largely lagged behind third-party alternatives, although the last major update, released in December, took steps towards making BBM more prominent and filling out the features list. If you're interested in getting the updated version, it's currently available in the BlackBerry App World from the link below.