The most recent Tomb Raider game has protagonist Lara Croft fighting off bad guys with a bow, one she can upgrade from a piece of wood with a bit of string into a sophisticated killing device. Obviously, it's a game so it can bend reality a little, but even so, you might be surprised at what you can make a bow out of.
An Instructables user by the nickname "Yoshinok" decided to cut up some old downhill skis, build a riser (the centre chunk of wood you hold), stick them together and fire arrows from the resulting product. Well, pose like he's going to fire an arrow from it.
In the tutorial, Yoshinok says that skis "are an excellent material to use for the limbs of a bow", citing the consistency of their construction and recurved tips.
If you're feeling in the mood to throw your own ski-bow together, you can follow his 13 steps to awesomeness, though I imagine there's a lot of work inside those steps.
Here's a video of the finished bow in action.