If you're looking for a team-oriented Twitter tool, here's some must-have features to consider:
The ability to log into and manage multiple Twitter accounts from a single application or tool.
Putting the team in “team tools,” multi-user support lets multiple tweeters work in the same environment and, if necessary, be individually identified.
Once you start pumping multiple Twitter streams, lists and contributors through a single app, the available statistics and metrics to mine begin to get interesting.
When managing multiple accounts, at times, it's easier to batch social media work, then send it out to the world over time.
If you are managing multiple accounts while trying to track different communities of interest via Twitter lists, good list management creation and tracking features are a must.