One of the most surprising things I've learned about Twitter is what a wonderful community builder it actually is -- in just months I've become a member of several communities with fun, fascinating people accomplished in the areas of society and culture I'm interested in.
Among the best is the amazing book community. It is erudite, welcome, goofy and diverse. It's easy to be involved too. Start with #fridayreads -- the "what are you reading?" tweets about books, audiobooks, magazines, cereal boxes, you name it. If you're reading it, tweet it and include the hashtag #fridayreads to be part of the wonderful @bookmaven weekend starter. There are prizes, and I've been fortunate enough to win one, but what's really rewarding is that #fridayreads is not snobbish anywhere on the genre/lit fiction spectrum and that it dramatically demonstrates that there are people who still love reading for its own sake.