Liberals and Others
Robert Ackland did an interesting study of the linking behavior of American A-List political weblogs. He found that conservatives link to each other; liberals link all over the place.
That gives conservatives a little more google juice, and that's worrying. But it's also what you'd expect from first principles: American conservatism has always been embattled and often anti-intellectual, while the defining characteristic of Liberalism is the possession of liberal interests.