Well, I had some fun in my youth with an Atlatl. When I was around 15 I made a very crude atlatl and one spear, a roughly four foot hickory salping with nothing but a notch in the back and a whittled point on the front. I chucked it at just about anything (remember, I was a teenager) and had an affinity for scaring the daylights out of the squirrels on our land. There was an occasion where the stars were aligned or something and I actually managed to thump a squirrel with it and almost sent the squirrel out of the tree, but I can imagine I would never be able to hit a squirrel again in a million shots!
My main interest was the simplicity of constructing my crude setup, I probably spent two hours on the "thrower" and an hour on the "spear". In a survival situation that seemed to be a remarkably short amount of time to create a ranged weapon with a lot of power.