HelloBrain
http://www.hellobrain.com/

"The world's intellectual capital exchange"

This site thinks in terms of whole projects and proposals, providing public and private forums for the negotiation. It attracts big buyers.

Buyers and sellers fill out detailed online forms to define the project. The site has an inference engine to match the qualifications of the buyer with the needs of the seller, and a discussion tool for negotiations. You can broadcast the process or keep it private.

Anyone can browse in and view the six figure proposals. You get discussion board access immediately for giving your name and email address. You'll see proposal details, bids, and first contact of the parties involved, but not much beyond that. Completed contracts are color coded blue and that's all you'll know about it.

Negotiate a price and the site will hold it in escrow, paying out only when both parties are satisfied.