RE: Native Americans...
i went on an archaelogical dig in upstate NY. I found a flint projectile point (they said they weren't sure if it was definitley an arrowhead) that was supposidly 4,000 years old. the thing was still sharp. but i was surprised at how tiny it was. Probably half the size of a modern broadhead. I don't know how they brought down deer with that but they did.