One interest of mine is programming languages, and more specifically, Lisp and Scheme. Lately, the blogosphere has produced a couple interesting blogs that tie to this interest:
Planet Lisp aggregates a bunch of Lisp-related blogs, while LtU is more general and more of a discussion site.
Related, I came to Lambda the Ultimate via Eric Lippert's Blog on Weblogs @ASP.Net. Eric is a developer at Microsoft who's done a lot of work on Windows scripting and the Windows script languages.