Assigning a task to multiple users

Teambox does not support multiple assignees for a task.

There’s a good reason to have only one responsible person for a task: If there are several assignees, responsibility gets diluted. We want only one person to know the task is waiting for an answer from them. “When everyone is responsible, nobody is”.

“At Apple there’s never confusion as to who is responsible for what.” In Apple’s parlance, a DRI’s name (directly responsible individual) always appear on the agenda for a meeting, so that everyone knows who’s the right contact for a project”. Source: Macstories

http://www.macstories.net/news/inside-apple-reveals-steve-jobs-anecdotes-apples-little-known-facts/

Basically you can send tasks back and forth, so that there is always just one person working on it.

Example: You want to design a flyer, Bob and Gill want to do design work on it.
Instead of just having them both designing, it is better to have Bob start, so then Gill can give feedback and then do something on her own or pass it to somebody else.

So passing the ball is more effective and you can save a lot of time compared to riding on several tracks at the same time.

More complex behaviors can be specified by comments, or adding watchers to the task.

You can add somebody as a watcher to a task by mentioning their @username. This way, they will receive email notifications each time there’s a new comment.