Here is what I really love about Twitter: Within 2 minutes of looking at math tweets, I have found either something I can use in my classroom or something that someone in my department can use in their classroom. Really - that is no lie!
Example #1: Finding alternative assessments that give each student something different to do is not always easy. When looking through Twitter in April of last year, I found an idea that I shared with the PreCalc teacher at my school. It was called the Birthday Polynomial. She used the idea and made it own. Plus we had tons of student created posters to decorate the math hallway. I think I got it from here: Birthday Polynomial
Example #2: (From about 5 minutes ago) I am going to be renewing my National Board Certification this year and I need to find more ways to get students to reflect on what they are learning and how they think class is going. While searching one of the suggested math blogs http://made4math.blogspot.com/, I found something that I can use!
You might be saying, "Sure - it's easy for you to find useful items, but I don't want to wade through tweets that don't apply to me." You don't need to! I organize my Twitter feed in TweetDeck. Here is a screenshot of my twitter feed as organized in Tweet Deck. This pic shows only 4 of my the twenty columns I have set up in Tweet Deck.
If you want to learn how to TweetDeck, here is a link to a youtube video and here is a link to a wikihow on How to Use TweetDeck.