U.S. Patent No. 7,457,767 (.pdf)
Issued yesterday (Nov. 25th), this is possibly the stupidest patent that I've seen in a while. And to think, this one was patented by IBM! Here's how it works (as so artfully shown in the flow chart - click the image to enlarge): you and your friends finish up a dinner at a restaurant, the waiter brings out the bill, and each person wants to pay separately. Everyone figures out how much of the total (plus gratuities!) they need to pay, and the waiter charges each person's credit card separately until the bill is paid. The end. Patent granted.
Why on earth would anyone ever want/allow this to be patented? The only reason that I can think of is that it's commentary from IBM's R&D department. Could it be that, with all the economic woes, they aren't paid enough and therefore have to split bar tabs? And come up with patently stupid patents like this one to meet their yearly quotas?