I blog. I read blogs. I think blogging is an important and amazingly personal way to connect with incredibly smart people around the world that one would otherwise have not been exposed to.
Every great intellectual movement of the past has involved a relatively small, diverse group of individuals putting together ideas and collaborating with one another. Consider in America the transcendentalists; Emmerson, Thoreau, etc., who knew and spoke with one another. Or in Paris, the philosophical circles of existentialism headed by Sartre and Simone de Beauvoir. We have always relied on one another for support-- for other heads on which to bounce our ideas. I personally view blogging and reading blogs as the modernist equivalent (at least in capacity) to such collaborations. Blogs are, when they are at their best, discussions about concepts and ideas. They are a way to pass on news, to report from one's window the world outside that may not be available to others elsewhere.
Thanks to blogging, I have a better understanding of history and it's implications in modernity. Thanks to blogging, I am able to access some of the smartest and most informative political and legal opinions in the nation. Thanks to blogging, I am able to learn about international issues in Africa and elsewhere. Thanks to blogging, I get tough grammatical questions answered. Blogging is a support system for feminism. And sometimes, it's just plain fun.
I don't think it's a waste of time. I don't think it's frivolous.