Thingiverse user sideburn posted "Invaders!" recently and they're way cool. If you have or have access to a 3D printer such as the MakerBot, RepRap, Dimension, Z-Corp, etc. then you can print out your very own Space Invaders ships*!
Thingiverse is a community site that encourages the free sharing of designs that can be made at home with (mostly) sophisticated tools or even small-batch manufactured depending on the license. It's open-source for tangible stuff.
*not actual size