Google is introducing a new app for the iPhone that will allow users to perform voice-based Internet searches. I'm trying to talk to Google about it to get a little more information than is available in the piece in the NY Times. Basically this appears to be like what Yahoo did with Vlingo for oneSearch earlier this year.

The first voice apps for the iPhone -- despite the fact that lots of companies have them in development or in the Apple approval pipeline -- were introduced by Dial Directions: Say Who and Say When. We wrote about both previously. 

In the realm of "free DA" we have:

• 800-THEINFO
• 800-Yellowpages
• 800-Free-411
• 800-Call-411
• 800-555-Tell
• Goog-411

Then there's mobile ChaCha, which is a full Web, voice search engine (with humans in the background).

In terms of mobile voice clients, there's Microsoft's Live Search, Tellme, Google Maps for BlackBerry and, as mentioned, Vlingo for Yahoo! oneSearch. The proof, however, will come in using the new Google iPhone voice-search capability, which is based on the same recognizers as Goog-411. 

There's a lot more to say about all this, including about some research we conducted on voice search and the consumer appetitie for voice, that is part of a forthcoming report. 

For now, I've offered some additional thoughts in my post at Search Engine Land as well.