There are so many ways that Twitter, a popular micro blogging website, can be useful for teachers. I'll give a few examples of its use here just to get you started on this potential educational resource.
An article titled, On the Deeper Connections Built Into Throw-Away Questions, by Shelly Blake-Plock, discusses one of these great uses of Twitter. It talks about what as teachers we may call a "throw-away" question and how one of these seemingly pointless questions can spark a great debate among students through the use of Twitter. By posting one of these questions, such as: "Latin Students: How many museums can you find on Twitter? +10 pt coupon to anybody who Tweets 20 museums with collections in Ancient Art!", a teacher can really motivate their students to start thinking out of the box and using a site like Twitter as a resource (Blake-Plock). The next day so many students will come into school with a list of museums to get their bonus points and for once they will (not admittedly) like doing their homework cause students enjoy the use of social networking sites.
In Educational Twitter Chats Calendar, the author writes about using Twitter for educational chats. These are basically a way to connect with other educators who are interested in the same topics as you. For example, if you want to know about using Twitter to teach Spanish, there may be a chat specifically about that. So you would go on the chat and be able to discuss the topic with other teachers and get new ideas about how you would use Twitter for a Spanish classroom. The article also mentions a new calendar feature that can make it easier for teachers to keep track of all of their educational chats on Twitter.