I have put a bunch of photos of good pit designs onto our team photo-sharing web site at
http://rollingthunder.smugmug.com/gallery/1414921 from the 2006 Atlanat world championships. In our 2nd year, we created a really cool pit which won us the imagery award at the Boston regional (along with our team camouflage uniforms, etc). See some pics here:
http://rollingthunder.smugmug.com/photos/67064497-S.jpg
Some thoughts:
1) Portability and easy-setup is critical, especially if you're going to Atlanta championships via public transportation.
2) Abide by the rules as defined by FIRST and expect the rules to improve year-after-year. FIRST now mandates a maximum height of the pit. There is now a "typical" 10'x10' maximum footprint for a pit, but not all regionals have this (yet).
3) Safety is the next consideration. Pits should be stable, and some regionals get a bit fussier about flameproofed fabrics, spotlights in the pits, power strips, etc. Your team needs to have EASY egress from the pit with the robot on the cart (height clearance?). Therefore, side curtains, etc are a real pain in the #$%^&.
4) I strongly advocate NOT putting up side walls nor a "roof" since a) it blocks out a lot of light and b) is somewaht unfriendly to your teams next-door.
5) Many teams use PVC pipe (electrical schedule 80 or plumbing sched. 40) which is OK, but only in shorter lengths. Consider cutting sections into easy-to-handle lengths and then use a "coupling" and a bungee cord at each break such that the pit poles can be dismantled like a mountaineering tent. Go check out camping stores to see tent frameworks.
6) Be sure that your pit does NOT stick out into the aisle. Think creatively about making shelves, organizers, out of fabric with pockets instead of rigid materials in order to ship them. Here's an example of a collapsable shelf unit:
http://rollingthunder.smugmug.com/photos/67064483-S.jpg
7) Additional thoughts:
-- Make pit components fit into the robot crate (along the side; securely-mounted with Bungee cords) as long as it doesn't make the crate weigh too much
-- Re-use the doors of your robot crate as folding tables. There are leg kits available on the Internet which can be mounted to the inside face of your robot crate doors. be sure they're stiffened to use as tables, not just 1/2" plywood....
-- Figure out a way so that your tool boxes become "bases" for table, etc. Same holds true for those big plastic tubs.
-- make sure that you have a way to show-off your team's literature out front, a dispenser/bin for button hand-outs, display stuff for judges walking by. Just go to a real trade show and benchmark what they do...have fun.