Ok, I've already got mine, but this is a good one to have. Cheap too:

An LED headlamp. There's a ton out there, but I really like my Black Diamond Zenix lamp linky.

These are great for working on the truck. I use it in the garage at night, as well as for BBQ'ing. Got mine on EBay for under $30. BTW, the "Hyperbright" high-power beam is easily as bright as a mini-mag. Seems brighter in fact, but I think that's because of the color of the light.

--Dan