While picking up some mobile one from Wally world a few days ago ($21 for five qts), I decided to take a look at the camping section. Always have to look to see if there's any new items I just have to have! Well, I did notice that reliance, the company that makes the water jugs, has come out with a porta potti. I have always been a big fan of the P.E.T.T. system. See:
http://www.amazon.com/The-PETT%C2%99-Portable-Environmental-Toilet/dp/B001CWAIJI/ref=sr_1_50?ie=UTF8&s=sporting-goods&qid=1277923745&sr=8-50

But they are expensive. Typically about $80 and up.

This product from reliance is based on the same principle (tripod design) with collapsible legs and can still use the W.A.G. bags that the P.E.T.T. uses. These are basically plastic bags with some gel material to absorbed liquid that are biodegradable. You just toss them in the dumpster or bury them when you're done.

Here's the link to the bags:
http://www.amazon.com/Phillips-Environmental-Products-G-Bag/dp/B002ZNBGPS/ref=pd_sim_sg_1

The reliance product sells for about $28, and appears to be very similar to the P.E.T.T., supports about 250 pounds and is actually smaller and lighter in weight.

This is an item I don't use all that often, but it's nice to have when you need it. I've never been a big fan of hauling my own waste, so this is a nice alternative to the "blue liquid" types, and takes up very little space when folded.

Cheers.

Troy