Andrew Sullivan's blog is many things to many people, and I continue to count it as one of my favorite daily reads. He's taught an awful lot of people how to blog, many of which have then gone on to teach others how to blog, and so on. But what I appreciate most about him is the way his site functions as a gateway from the relatively cozy community of the blogosphere to the big world beyond. When I was first building my own audience and an acquaintance came up, started talking about a piece I'd written, and exclaimed something along the lines of, "I had no idea you were a journalist!", nine times out of ten, they'd seen my work linked at Andrew Sullivan.
I know I'm just one of the many young writers who've been handed a ticket to wider readership thanks to a timely reference from Sully.