I'm new to twittering, but I've found some interesting and, in some cases, hilarious ones to follow. For cat lovers there are Sockington and his "friend" Pennycat. As is typical of cats, Sockington is very full of himself and Pennycat never misses a chance to point that out. Sockington and Pennycat also have their own websites.
I am also following two foreign language twitters to try to buff up my Spanish and French - French Byki and Spanish Byki. Sort of like a word a day calendar, but on Twitter. And each one has a link to a website where you can hear the word spoken and see and hear it in a sentence. I may have to sign up for Italian, too!
AmericaHandmade is another great one - spreading the word about buying American Handmade items. She features lots of different artists and crafters.
I also follow a lot of my fellow quilters, Etsy, Facebook and, of course, Dr. Phil (?). I'll keep adding to my favorites list as I find more.