i go to the national gatherings whenever they're held out west here and can say i have never heard of any such trades going on in any kind of scale worth mentioning. it happens but it's not a common occurance and is usually not done with strangers. but it'll be more than worth your while to just show up with your camping gear and settle in for a few days. most are really cool people who prefer living off the grid (but beware of what we call, 'drainbows'...lazy sponges living as easy as they can, same as any other community. if the camp is in good shape and people invite you into their camp then i'd move in for a few days if it was around me...it's an excellent way to learn camping and survival skills.

here's a link to the rainbow news group where you can find more info and links (and the typical message board bullshit too)...
http://groups.google.com/group/alt.g...rainbow?hl=en&