I love crocheting, knitting, and yarn bombing!
This was a recent group project for one of my classes--Spring 2013. We turned a trash bin into a hazmat barrel with ooze, slime, tentacles, and eyeballs coming out of it. Each person did a part of the piece. I did the tentacles, eyeballs, and the top part of the barrel.
I would love to do more of these projects, but it takes a bit of planning and work. I'll probably just look for some local yarn bombers (if there are any events being planned) and see if I can work with them.