Be careful when adding shelfs and storage inside the crate. Go overweight, and you'll have some hefty bills to pay drayage and FedEx when you uncrate your bot at the regional.
We use a crate, with a pallet base (and a sheet of plywood over it) then its built up using 2x4s that were ripped in half (2x2s .. well .. 1.5x1.5s) and then plywood over the sides. The thickness of the ply has slipped my mind (which is pathetic since I was putting the crate together tonight), but it seems like it was 1/2".
Inside, we have a small plywood box for the batteries, and then the robot. Over the last 2 years, we've mounted the bots differently (last year we made brackets that physically bolted the robot to the crate; first year we used lag "eye" bolts and ratchet tie downs). One thing to remember, secure any appendages. If you have something that moves (such as an arm), make sure you secure it to the robot or the frame some how. Stuff WILL shift inside the crate. Something else worth mentioning that we have discovered .. the crates aren't kept very dry. Back when FIRST gave us the drill motors, ours rusted in the crate. Steel shafts started to rust/oxidize. This is something to consider when you're thinking about shipping tools. Unless you really want to pay for the extra fees, I would recommend bringing your tools to competition anyways.
With that said, heres our crate (with our 2004 bot)
