LinkedIn has always been the social network site that was closest to the "original" (or pre-Web 2.0) idea of networking – the professional kind. So, since a lot of people start thinking about callings and careers before they're 18, it makes sense that LinkedIn should be open to high school students. This week the social site announced it would open its doors to people 14-17. LinkedIn also … [Read more...] about LinkedIn adds teens & university profiles