Ari Paparo via the Waypath blog via Michael: Big List of Blog Search Engines.
While all of them crawl blogspace, many don't just perform blog search.
Here's my short list in alphabetical order, along with what I use these
engines for.
Tracking inbound links from weblogs to just about anything, using the Technorati Anywhere! bookmarklet (a godsend).
Figuring out who else follows that new blogger on the block.
Update (Jan. 9): As Ross
reminded me in his Linkorama, Google is a good blog search engine too.
Just append "blog" or "weblog" to your search request. And (says Alf) if you don't want blogs, append "-blog".
Following up on Why people blog: Merci Martine for the pointer to Lilia's Why I blog posts. And in her contribution to last year's blogTalk conference,
Lilia also ran a survey to find what motivations people had for
starting and pursuing blogging. You can find results starting on page 3
of her paper "Blogs: the stickiness factor".