What is it?

Time for another contest! Tell me the nomenclature of the thingee pictured, and you'll win a Blog Ad on my sidebar! (If you don't have a blog, I'll think of something.) Email your guesses to me at cowboyblob--at--yahoo-dot-com. Again, I'll accept only two guesses from any address; my reason for this is that I'm really not looking for guesses. You're at a computer with an internet connection--if you don't know the answer off the top of your head, there are plenty of places you can look for the information using the visual cues in the photo. If you're one of the rare people who know the answer right away, good for you! I want to give the rest of my visitors a chance to win, too.

My previous contest is still open. Bueller? Bueller?