I follow characters sometimes like S.A.R.A. from Eureka.
There are authors that I follow, more likely their blogs than twitter because I like what they write.
There are Tech people like Leo Laporte, Sarah Lane, Tom Meritt, Amber Mac, Jason Howell, Gina Trapan, and Jeff Jarvis that I follow because Twitter and now Google+ are a good part of how they report the news.
There are some mainstream reporters and citizen reporters that I follow. It used to be more their blogs, with twitter also now they are all over Google+.
There are also celebrity teachers if you will. These are people that really supported and pushed the idea of using twitter, blogs and podcasts to form Personal Learning Networks. These are the only people that I kind of feel like I know. That is because we have had actual conversations through blog comments about topics. A couple of times the have posted links to my blog posts. I've used their lesson plans, and they have given me feedback about mine. If I ever get to go to ISTE or other teaching conference, I would feel comfortable talking to them.