I copied this quick comparison of consulting websites from another blog here. I have used some of this sites in the past, both to obtain work and to distribute work. I copied here for future reference.

	Elance.com	Guru.com	oDesk.com	RentACoder.com
php projects	1831	271	887	425
Technical Writing projects	18	89	42	51
Sales & Marketing projects	302	127	No category	147
Alexa rank (lower is better)	4960	14833	13768	18859
Free option	Yes - limited bidding	Yes - higher fee on jobs	Yes	Yes
Fee	6.75% to 8.75% based on volume	10% for free membership level. 5% for premier level.	10%	15% or $3 minimum. Lower rates for direct payments and bonuses.
Premier Membership Fee	$9.95/Month. Up to 20 bids (up from 3). Up to 2% fee discount	$29.95-$99.95/quarter depending on field for each subject area (profile). 50% off for annual membership	None	None
Limit on bids	3 for free level/mo. 20 for premier. Fees for additional bids	10 for free level/mo. 100 for premier. Fees for additional bids	None	None
Dispute Resolution	When Escrow service is used	When Escrow service is used	Hourly jobs only	Yes
Escrow service	Yes	Yes	Hourly jobs only	Yes
Online tests & certifications	Yes	No	Yes	No

And some additional sites from another post that I read:

1. All Dev Jobs
Mainly web development projects.

2. Authentic Jobs
A fairly active job board that attracts some great project postings.

3. Freelance Switch
The freelance switch job board is very active, and contains a wide range of development jobs. There is a catch though: It costs $7 a month to reply to any of the postings.

4. Javascript Ninja Jobs
This is a job board for freelance javascript jobs from John Resig, the author of the jQuery library.

5. MetaFilter Jobs
Freelance development projects, mostly consisting of web and mobile application development.

6. No Agencies Please
Primarily a site for UK based work, but there are lots of remote projects. Includes a whole range of different development projects, and isn’t just limited to web development.

7. Programmer Meet Designer
A site that aims to introduce programmers to designers. Many of the projects that get listed are for skills exchanges (eg. you code my site I’ll design yours. There are occasionally paid jobs though, so it’s worth checking the site every so often.

8. Search Web Jobs
Lots of web development jobs, primarily involving CSS, HTML, PHP and MySQL.

9. Smashing Jobs
The job board of the online web development magazine.

10. Web Directions Jobs
Web development jobs. Mostly PHP and Javascript.

11. Plasis Jobs
Plasis Jobs aggregates freelance development jobs from 8 of the above 10 sites, so instead of having to check lots of different sites everyday to make sure you don’t miss out on a great new project you only need to check one! It also filters the jobs so that only freelance development jobs are shown, rather than full time jobs, or jobs for designers.