The article, Blogs ‘essential' to a good career says a well-executed blog can help you find a job by establishing you as an expert. The key here is “well-executed.”
Blogging is great fun, and can help potential hiring managers discover another side of you. And, if your blog isn't well-written, doesn't link to others, and talks enough about off-topic issues, your blog may not help.
But I'm an optimistic person. So if you're a candidate looking for a job, start blogging!