scoyoc5,
I've found my best deals on Craigslist. The trick is to have an general idea of what you want then check daily over the course of a few months.
I recently bought an REI Hubba Hubba tent for 50% off retail following the above method. I didn't specifically want the Hubba Hubba, but it was one of several tents that would work.
As far as finding used gear if you don't have extremely specific requirements you should be able to get good deals on tents, sleeping bags and packs. The other stuff is harder to come by used (stoves, cookware, misc crap). For that stuff I just look for the best local sale or price on the internet.
