This week's collaboration with What is It? Blog brings us this .... clamp! But it's not just any clamp, this tool actually has a very specific use: can you guess what that is? Post your answer in the comment section - no URL, please! Let others play.
Update 3/30/07: It's a book clamp to hold large books open while you read it! Here's the patent. No one got it right, although Jen #23 was the closest.