Using Social Networking Technology in Teaching

I am very interested in social networking and how it can be incorporated into my teaching instruction. I signed up for Facebook, Twitter, Myspace and several other social networking and I use them although not all the time, and I know this is very popular among students now as well (particularly undergraduates). I keep thinking ways to capitalize on the popularity of these social networking things in teaching instructions. If we are somehow able to incorporate things like this into our courses, could we make the courses more interesting and engaging for students? I found some people have succesfully done this. Check out these links:

1. Twiter goes to College
2. 25 Ways to teach with Twitter