I second Brettski's choice.
A personal favorite is my air powered ratchet. Sure makes working on my army of wheeled implements a lot quicker and easier. I'm waiting for prices to drop on battery powered ratchets.
I just got a 12v pump from HF, and that puppy puts out some water. At 39 bucks, it's hard to beat. I use it to pump water from plastic drums, because I have no electricity at my barn.
