I was watching Nature on PBS and was blown away to learn that crows can use tools; More specifically, using tools in multiple ways, or in sequence to achieve a goal. Previously only chimpanzees and elephants had shown this ability, but crows can now be added to the list.
The crows are masters at shaping twigs to pull grubs from hard to reach areas of trees. Apparently this is somewhat rare in itself, but the real discovery is the use of tools in a sequence. Studies seem to focus on "New Caledonian" crows and there were examples of crows using one tool to extract a second tool which would then be used to get food from a confined space.