Well, looks cool enough, and you don't have to mark this as FAN ART you know. It's not a fancy mantelpiece-design or something. It's called "Newton's craddle" and is the basic set-up for visualising Newtons third law: Action equals Reaction, and the conservation of momentum and energy. No-one can slap copyright on that. Have a look on [Wikipedia](http://en.wikipedia.org/wiki/Newton%27s_cradle) :)

Wish the WW1 albatross wasn't "fan art"... Can't use it in opensource game because the ww1 plane somehow is "fan art- no commercial" :(