Keith Robison plays around with social networking web sites in this post at Omics! Omics!. He’s moved beyond LinkedIn to other web sites, like SciLink, Spock, and Doostang. At Doostang, though, he ran into a few problems inviting people to use the service ("Who knows how many Nigerian finance whizzes & providers of lists of MDs I'm now linked to!" he says). While Spock is a search tool for all, Doostang is only for 20- to 35-year-olds.