Discussion forums allow teams to create forums and post messages, automatically alerting the recipients via email. This can greatly increase team communication.
Many software development teams will create a discussion forum for each release of the software they are working on. Then each day, team members post questions in the forum. Everyone enrolled in the forum receive an email regarding the forum posting (assuming their email alerts are setup) and the person knowing the question will answer the forum and everyone sees this collaboration in action.
It is also beneficial to post daily updates to the forum so that team members know what code modules were changed, what specifications they related to, and the status of how the coding in that area is progressing.