On one of the forums I frequent, there is a thread that has been going on for about three years now on arrowheads found on the ground.  Mostly posted by folks in Colorado and Texas, there are some real nice finds.  I thought I'd share.

These are some unique finds of carved object, of unknown use.  What stories they could tell, no doubt.

 A find in situ, from a corn field.  Apparently plowed fields are prime spots to uncover ancient artifacts.

My own recent find occurred when I took the kids paintballing last fall up in the foothills near where we live.  While they did their paintballing wars, I hiked out among the hills, and by chance stumbled upon several grinding holes on a low ridge.  On the remote chance of finding the pestles, I looked around, and amazingly enough found two of them, left there by the indians who know how long ago, where they lay until I came along.  I put the best one next to the most obvious hole, and took the picture. I left it all there, perhaps to lay for another 150 years until the next guy wanders by.

The view from the grinding holes.  Pretty nice as a spot to sit and make acorn paste.