Shapeways has a whole library of items that other people have designed that you can print. I ordered several as stocking stuffers at Christmas. Holding them in your hand is a good way to get what this whole 3D printing thing is about.
That's awesome but it's not even on Shapeways anymore, it's actually made the jump to traditional manufacturing. And for some reason, it still cannot be sold outside the US. WTF?
They were excellent. The Code Prize does feel very nice in the hand. It feels solid, and the inner parts don't move at all as you'd expect looking at it. The Gyroid is remarkably small and delicate, and my son (the gamer) liked the Mario Mobious.
I second this. http://i.materialise.com/ is decent too, but Sculpteo is the best I've used. Their standard service is very fast, and the prices for the small stuff I typically print is much cheaper than the others.
The items I ordered:
http://www.shapeways.com/model/24470/gyroid.html
http://www.shapeways.com/model/335195/the-code-prize-fire-co...
http://www.shapeways.com/model/683524/super-mario-mobius-str...