Great as an exit ticket or tool for short summaries - have kids Tweet about historical events, people, and documents!
Can be used as exit tickets, printed as post-it notes, or pinned on a bulletin board. A quick and easy way to see if kids can summarize information (in 140 characters or less!)
For extra fun - purchase small heart stickers and allow students to "like" other students' tweets!
If you're really inspired, upload to a place like VistaPrint and have your own decks of post-it notes made!