Twitter can be a great source of professional development, inspiration and collaboration for teachers. Just the other day I was looking for a hands-on activity with which to demonstrate elastic potential energy and energy transfer and so I tweeted for ideas. Here are some of the wonderful suggestions I received from the Twittersphere. Thank you everyone for your contributions!
Wind-up butterflies
Image credit: youaremyfave.com. Full instructions available here
If It's Green Or Moves 