Non-Semantic, P2P-enabled versions of Google, eBay, Yahoo et al. can shift power to the user, especially since P2P eliminates the need for massive corporations to spend massive amounts of money on server farms to process the users’ transactions. Each user provides a piece of the server farm. The Web’s reported 2 billion users mean that a P2P version of Google can run on a server farm of at least 200 million servers. That is significantly more servers than Google can ever have.
So you wanna take on Google, eBay, Yahoo et al…? Then build a P2P version of any of their core services.