My recent work with Tackle-bot, a robot frame built from a fishing tackle box, started me thinking about other ways to build a robot frame for those of us who are mechanically impaired.
Flower pots work quite well, actually.
Stop by Freddy's and check out the plastic pots in the nursery section. You can get some really cool looking pots for very few bucks. Also look at the detachable drip pans, normally sold separately. Turned upside down, these would make a short, wide base for a robopet or for an experimental platform. You can take a box made of ABS, hack out places for the wheels and front casters, and build a complete robot inside.