I came across a couple of academic blog lists this morning via The Chronicle of Higher Education's Wired Campus blog.
Crooked Timber, to which pioneer NUS academic blogger John Holbo contributes, maintains an extensive list of academic blogs. These cover political science, political theory, sociology, public policy, economics, finance, philosophy, linguistics, psychology, law, history, computers, media, communication, anthropology, geography, education, business administration, marketing, industrial relations, literature, language, culture, the Classics, religion, library science, music, biology, medicine, physics...
UPDATE: Crooked Timber's list has been removed.
And I'll stop here because I'm out of breath. Suffice to say, the blogs cover the breadth of the main academic disciplines.
I mentioned a couple of resources. Here's the second. Academicblogs.org is another place to look for academic blogs in your respective field. Although it claims to draw on various sources, including Crooked Timber, the various subsections seem to be shorter (quality control at work, perhaps?) than Crooked Timber's list.
What's interesting about Academicblogs.org is that it is a wiki. This means that it is freely editable, and you can contribute to it.
So visit your fellow academics' blogs and be inspired!
P.S. Some of the featured blogs are the authors' personal blogs. Not that personal is impertinent.