Fun Orbital Simulator

Be careful, it's kind of addicting.

http://phet.colorado.edu/simulations...y_Solar_System

Yep, those Phet simulations are great.
Also: http://www.bigideafun.com/penguins/a...paced_penguin/

I'm scared to touch it. Last time I wound up digging Dwarf tunnels for a month. I'm not going this time.

Funny. I think our physics class has this...