project bidding sites

Anyone have experience with project bidding sites, such as:

http://guru.com/
http://www.rentacoder.com/RentACoder/default.asp
http://www.elance.com/
http://getafreelancer.com/


Most of these sites charge a membership fee in order to be able to view 
the details of a project or bid on it. I'm quite skeptical that they're 
worth the investment.

In casual browsing at sites like rentacoder.com it seems that most of 
the projects are low budget and are mostly bid on by college kids and 
off shore workers. Another site seemed to focus on high-end enterprise 
projects that require lengthly proposals. Ideally I'm looking for 
something in between.

In theory, project work should be a good niche for Perl. Perl may be 
showing up on job postings with decreasing frequency, but for a project 
that doesn't mandate what language is used for the solution, you can 
take advantage of the speed of development Perl provides, and possibly 
underbid competitors. (See "Productivity and Perl", 
http://www.perlmonks.com/index.pl?node_id=170938, and the Paul Graham 
essays it links to.)

I'd be interested to hear of any good or bad experiences with sites like 
these.

  -Tom