How to search for whatever continues to be one of the most fascinating sides of the Web.

Google’s new service (in beta, naturally) is available both at google.com/blogsearch and search.blogger.com. Google blog search scans content posted to blogs and feeds in virtually real-time, according to Jason Goldman, Google product manager for blog search.

“We look for sites that update pinging services, and then we crawl in real-time so that we can serve up search results that are as fresh as we can,” said Goldman.

Google defines blogs as sites that use RSS and other structured feeds and update content on a regular basis.

Although Google Blog search focuses primarily on content published to the blogosphere, it’s not a true full-text search across all sources, according to Goldman. This is because some publishers only syndicate excerpts of content via RSS. Google’s blog search indexes all of the content it finds in feeds, but does not attempt to access and index the full content available on a publisher’s web server.

I tried a search for Dvorak & Websense and got hits ranging from 2 days ago to an hour old.

Now that Google has launched blog search, expect the other major search engines to follow suit fairly quickly. All have been feverishly working on blog search over the past year, and now that Google is first out the gate the others will likely move quickly. I’ll circle back and take a closer look at blog search once all of major players have launched their services, most likely by the end of this year.