I have just spent more time than I have on this flash game called Perfect Balance. It's pretty neat. The goal is to place all the pieces on the board without anything falling off. On each level, there are some fixed structures from which you build and balance from.
Note that you can rotate pieces... when I first started playing, I didn't read the instructions and didn't realize it. Hehe.
Anyway, there's 40 levels divided up into two stages... Harmony and Inferno. So far, I'm having some difficulty on Level 18, Inferno. I'll give it another go later on. In the meantime, enjoy the game.