We just added a Twitter feed into our Moodle coursepage for Global Enterprise class, and the students really liked it. It was simple to do. Just go to www.twitter.com/goodies/widgets, and get the code for embedding a specific Twitter account. You can use a professor's personal Twitter account, or a more general one on a specific topic that's appropriate to your class.
Then go into Moodle, and add an HTML box, and paste in the code. It looks really nice, can be color-coordinated with the design of the page, and it is a great resource for students.