For anyone interested in building a lightweight yet strong crate, my team published a white paper this year which is a good, cheap, strong, and light crate. It's also easy to open quickly at competition. About 10 teams in the Boston area used this design, and all of them had no trouble with overage charges, or damage in transit.
The white paper is here:
http://www.chiefdelphi.com/media/papers/1781
If you are going to build a new crate, I highly suggest you at least look at this design. If you don't use it exactly, you might be able to take some of it's better features and incorperate it into your own crate.
Maybe that can help prevent some people mishaps in the upcoming season :-P
- Toby, Boston University Overclocked 246