Nick Bilton/The New York Times

Among the technology entrepreneurs announcing new products at the Web 2.0 Summit in San Francisco, there was an unlikely guest: M.C. Hammer, the rapper.

On stage at the conference Mr. Hammer announced a new Web service called WireDoo: a search engine that adds relationship information to search results. For example, if someone searches for the word “car” on WireDoo, they will see results for topics related to a car, including insurance, pricing and consumer safety ratings. Searching a stock symbol will show related investors and mutual funds.

Mr. Hammer said WireDoo, which is currently still being built and not available to the public, is not trying to compete with established search giants like Google, but hopes to offer a “deeper type of search” that can show relationships to queries.

Mr. Hammer noted that he has started building and investing in technology start-ups as he sees the business potential of data-driven companies on the Web. “No one is playing for singles anymore,” he said at the event, noting the huge returns investors can reap from technology start-ups.

Entertainment celebrities, including Mr. Hammer, Ashton Kutcher and Mike Tyson, have increasingly joined the tech start-up scene in recent years.