Minister, sales charts-topping rapper, stylish innovator, funky headhunter: all those words can be used to describe the oddball career of MC Hammer. But there are a few more that you may not know about, like, say, “tech start-up investor.” Hammer unveiled his newest scheme at the Web 2.0 Summit in San Francisco yesterday; the interestingly named WireDoo is a Hammer-powered search engine, and it’s all about relationships.