Okay after 5 years of experience, I think we've finally got a simple Pit design and system down. 10'x10' frame made of PVC (we painted it Green) with no segments larger than 45" for fitting in the crate with a robot. Plastic shelves hold many of small bins of fasteners and spare parts (heaviest ones on the bottom of course). Rolling Tool chest on opposite side of pit. And the plastic shipping bins you get each year are used to pack the tools and parts can then be stacked on top of each other and place a table cloth over and whalla you have a couple of nice end tables to put out buttons and handouts. We also had a projector running video highlights from the past competition. I've seen some way cool pit areas, way cooler than this, but this was cheap (excluding the projector!), easy to setup and transport, and made the area look nice and still functional.
Here's a pic