After the burst of the dot-com bubble in the autumn of 2001, the World Wide Web has gone through some remarkable changes in its organizational structure. Consumers of data and content are increasingly taking the role of producers of data and content, thereby threatening traditional publishers. A well known example is the Wikipedia encyclopedia, which is written entirely by its (non-professional) users on a voluntary basis, while still rivaling a traditional publisher like Britannica on-line in both size and quality. Similarly, in SourceForge, communities of open source software developers collaboratively create new software thereby rivaling software vendors like Microsoft; Blogging turned the internet consumers of news into news providers; Kazaa and related peer-to-peer platforms like BitTorrent and E-mule turned anyone who downloads a file automatically into contributors of files; Flickr turned users into contributors of visual content, but also into indexers of that content by social tagging, etc. Communities of users operate by trusting each other as co-developers and contributors, without the need for strict rules. There is however one major internet application for which communities only play a minor role. One of the web's most important applications — if not the most important application — is search. Internet search is almost exclusively run by three companies that dominate the search market: Google, Yahoo, and Microsoft. In contrast to traditional centralized search, where a centralized body like Google or Yahoo is in full control, a community-run search engine would consist of many small search engines that collaboratively provide the search service. This report motivates the need for large-scale distributed approaches to information retrieval, and proposes solutions based on keyword auctions.