“Human-powered” mobile search engine ChaCha announced today that it has integrated voice search capability. The company started in late 2005 as an online search engine that tapped human operators to return results, with the thought that directly answering natural language queries differentiated it from the machine-powered search engines that rule the world.

But after realizing that trying to change users’ online behavior is more than a difficult proposition, it shifted its focus to the mobile search environment. Not only is this virgin territory (relatively) where users’ habits and expectations have yet to be formed, but there is a great deal of growth expected here, as we and others keep saying.

ChaCha’s mobile product, launched in January, is a text-based service that allows users to ask any question, which is then answered by human operators and texted back. Voice capability now makes it even more attractive and broadens the use case to include searches while driving or at other times when talking is preferred to texting.

Talking the Walk

It will be interesting to see if this brings the product into the range of appeal of those who are inclined to use directory assistance. The experience is in fact similar to automated DA queries such as Goog411, but it allows for a greater universe of queries, beyond “city and state” (i.e., “Who is pitching in the Oakland A’s season opener against the Red Sox tonight?”).

Other uses have come to light at the CTIA Wireless Show this week, according to President and Cofounder Brad Bostic, as many large brand marketers have expressed interest in using it for specific types of searches. These could include a virtual information desk at theme parks where visitors can text in park-specific questions, or a Weight Watchers application that lets users text names of various foods to have their “point values” texted back.

“One of the keys for us is to build partnerships for big brands and big user bases,” says Bostic. “There will be some creative ideas for how they can use ChaCha in different ways.”

The company is close to closing a deal with Indy 500 to have its service used for specific searches related to Indy Car racing at Indy events. In addition to these licensing deals, it will also monetize with transactional-based advertising such as appointment scheduling, restaurant reservations or travel bookings.

“Say I call and ask for what time a Southwest Airlines flight is from Las Vegas to Indianapolis at 5, and results are returned for an AirTran flight leaving at 5 and a Southwest flight at 6,” says Bostic. “This could then carry forward into a process of completing the transaction, possibly through a tie in to a third-party site like Orbitz.”

Location, Location, Location

There are clearly lots of possible local applications along these lines. The local appeal can be enhanced by texting “set loc” to the service, which remembers your explicit city or ZIP for future local searches and finds answers and human guides accordingly.

This local relevance will only grow, according to Bostic, as location awareness (GPS and triangulation) will be integrated to make local searches smarter. Location awareness, as we’ve mentioned, also knocks down an adoption barrier, and will be another enabling technology to prod mobile local search along in its slow march toward mainstream adoption.

So all this looks good on paper and holds up to the few test queries we gave it. The proof for ChaCha will be in getting users to adopt it. Here, a boon could come in the overall growth expected for mobile search, including voice search applications, which will get more mainstream exposure through the promotional efforts of Goog411 and Microsoft’s Tellme.

Bostic is seeing positive metrics in repeat usage (55 percent after the first query) and word of mouth (70 percent referral rate). After all, despite the hype about iPhone and smartphone adoption, talking and texting are still the primary functions used on mobile phones.