We have a Luggable Loo, which is basically a 5 gallon bucket with a toilet seat. It's cheap (actually cheaper than building a groover from an old 20mm ammo can) but also simple and does the job. It's not something you'd substitute for a real chemical toilet or outhouse, but also takes up less space. We use standard WAG bags available from various places, PETT, etc. The toilet and enough bags for a couple of weeks all fit inside the bucket. We don't have a privy, but borrowed Uncle Ben's for Rubithon. Normally we'll just carry the toilet out of sight, but then again we're usually not in a big group setting. For CM or the like you probably want a privacy tent.
'91 Pickup - Imelda
'08 Tacoma TRD - Donna
'09 Kawasaki KLR650
'12 Gunnar Rockhound 29
"Our task must be to free ourselves from this prison by widening our circle of compassion to embrace all living creatures and the whole of nature in its beauty. Nobody is able to achieve this completely, but the striving for such achievement is in itself a part of the liberation and a foundation for inner security. " --Albert Einstein