Back in June, Freelancer.com added a contest option for logo design. While crowdsourcing design remains controversial (especially if our reader comments are any guide), the option has proved popular and Freelancer is now offering across its 18 design categories.
Under the contest model, you create a design brief and pay a fixed fee to list it. Any designer who wants to can accept the brief; you pay the prize fee to the design you like best, and the same fee again if you want to use more than one. Pricing varies by category and depending on the turnaround you want (you can see some indications in the picture), but there's a "generic" category starting from $100.