I am only posting this because I haven't seen it on anyone's blog yet! A colleague shared the link with me on a listserv. It shows a man juggling inside a big equilateral triangle made out of wooden struts. It makes me think about how my 8th period freshmen (9/12 of whom are boys) like to spend the few minutes before the bell rings bouncing my rubber band ball against the classroom wall - I try to get them to stand at different distances away and talk about where they have to bounce it to get it to each other.
Anyway...this video could be the start of a beautiful geometry lesson.
If people watch this and get ideas about where to take a lesson from it, I'd love to discuss it in the comments!