I recently showed my MBA class how to use Twitter. On the whole, they were like many people who haven't experienced Twitter in that they were resistant and weren't really sure that it would be useful to them. However, they are now enjoying the platform and using it to communicate with each other on projects and also with the authors of their books. I think Twitter is a great way for students to connect with others and build their own personal learning network.
Here's an useful article to those new to Twitter: 25 Ways To Get the Most out of Twitter.