If you haven't considered using Twitter in your classes, I'd encourage you to think it over. Even in grad school, the idea of using Twitter for language teaching appealed to me, and I even did a few projects and lesson plans that incorporated Twitter.
It wasn't until my first year of teaching at the University of Oregon that I actually decided to try it out with students. Initially, we used Twitter in class to talk about Extensive Reading selections. I wanted to build classroom community and drum up some more enthusiasm about the books students were reading, and I thought that Twitter could be an excellent avenue for doing so.
This year, I've been using Twitter in the class with my Reading 100 students. Twitter is especially useful for this population (mostly Saudi) because the majority of my students already used Twitter for personal reasons. Their reading abilities are rather limited, so navigating a course management system like Moodle or Blackboard would be challenging for them. Twitter is probably the easiest way that I can get them to access links and resources that I want them to use. It's also a beneficial way to switch up a somewhat normal classroom activity like dictations or answer reading comprehension questions. I think the one caveat when using any sort of technology in language teaching is to work hard to ensure technology is being used for its own sake, and that there is a greater pedagogical reason to choose to use a web 2.0 tools. Often, I find with Twitter, the reason using it makes so much sense is because I am able to provide feedback more frequently and faster than if I didn't ask students to Tweet.
What can you envision using Twitter for in your classes?