The Gillmor Gang — Robert Scoble, Kevin Marks, Dick Hardt, and Steve Gillmor — got all LinkedIn in the wake of the startup’s successful IPO. Amid the fear mongering about another tech bubble, it seemed more likely that LinkedIn was the first of at least a trio of big social plays going public. Facebook and Twitter seem no brainers, each with their own dynamics in terms of revenue plus virality. And then there’s Groupon and maybe Zynga.