Ever since I made the leap from tech journalist to blogging executive, my inbox has seen a rash of LinkedIn requests. Maybe this has something to do with the fact few people want to network with a journalist. In any event, LinkedIn is one of those companies that has quietly become one of the more successful players in the social networking market. In the past year, its membership has doubled to more than eight million people, and the company expects to hit $100-million in revenue by 2008. Business 2.0 has a profile about the Palo Alto, Ca.-based company and its co-founder Reid Hoffman in the latest issue.