Joshua Gans and Scott Stern sent me a fascinating market design paper called Is there a market for ideas?, which performs some admirable intellectual arbitrage. They seek to combine modern insights on the unusual properties of intellectual property with some of the recent conclusions from market design.
They argue that some of the properties of ideas themselves make it difficult to organize successful markets for ideas along conventional lines: e.g. "...a key property of ideas - the potential for expropriation - limits the potential for market thickness and lack of congestion identified by Roth."
Among the particular examples they discuss of market designs that try to solve these problems and make markets for ideas are the scientific incentive system ("Open Science"), open source efforts such as Wikipedia, and commercial projects such as Ocean Tomo (which runs auctions for IP assets), and Innocentive (which runs a marketplace in which companies can post Challenges in need of solutions).
Edit: the link in the quote isn't working for me. Here's a better link.