Google Voice Local Search, aka Google 411 Experimental or just Goog-411, a free telephone-based information service, has apparently been live in Google Labs for several months now, but of course a lot of folks didn’t take much notice until the ubiquitous TechCrunch finally posted about it late last week. Thanks to their influence, it’s been making the rounds of just about everything in our RSS reader, so we thought we’d give it a spin and see how well it handles a request in the Washington, D.C. area.

First, here’s how it works: Goog-411 can be accessed by dialing 1-800-GOOG-411. When prompted, you speak your city and state, and then ask for a specific business or business category. It’s entirely automated with no option to speak to a person, but you can always say “Back” and it will reset itself so you can try again if you get bad results.

In an unscientific experiment trying to locate a single local business, we called and asked for a listing for Duccini’s Pizza, one of our favorite locally-owned pizzerias. We thought it was a good representation of both a number we often call to get and one that would challenge the voice-activated platform. When prompted, we enunciated clearly: “Duccini’s”. The system seemed befuddled, and asked us to clarify by adding a category. So we said, even more slowly, “Duccini’s Pizza”. After a few seconds of thinking, Goog-411 came back with two listings for local outlets of Domino’s Pizza, which I think we can all agree is an unacceptable alternative.

We had better luck tracking down the number for Duccini’s with JingleLabs’ 1-800-FREE-411, which is supported by actual human beings. And we’re very interested to try out TellMe Mobile‘s interface just as soon as we locate a phone that supports it. Anyone out there have experiences with any of these free 411 services in D.C.? Share ’em in the comments.