http://www.harborfreight.com/34-in-2...-pc-68113.html
95% of FRC teams should have a set of these and use them often. We had a lot of 1/8th inch 2" x 1" aluminum last year that got cheesed significantly by some of our students that needed something to do.
We always try to come in under weight and adding some lightening holes only helps in a lot of areas of the robot. Cheese early, cheese often.