Frustration with Online Freelancing Sites

Like many people, I'm sure, I am always interested in making a little extra money on the side. I work full time, so I am not really available for "full scale" contracting engagements, but I certainly have plenty of time to provide remote support and consulting.

For a while I've been using/browsing sites such as Guru.com, E-Lance.com, and even the "Gigs" section of craigslist.org. So far, I have had just about no luck with these sites. It seems that the types of jobs that get posted are typically posted by individuals or VERY small companies who really have no idea what the market value of the work they're looking for is. Or else they're looking for someone to configure their home firewall for $50 or something. Maybe I'm a snob, but that's just not worth the effort to me to go through the paperwork of dealing with something so low-end.

Is there any hope for sites like these? I know the work is out there. I have friends who have stable part time gigs, but they didn't find them online. Perhaps I'd be better off going out and pressing the flesh at business mixers, and I may end up doing just that. But it seems like the online freelancing sites are a good idea in theory. Why don't they work? Does anyone have success with these places? Inquiring minds want to know.