Google's voice recognition app finally arrived for the iPhone. You can download it from the Apple itunes store here iTunes

Google’s search-by-voice application allows users to speak into their iPhone to submit queries to Google’s search engine. This will appeal to users who find it difficult to type using the iPhone keypad, especially when we are so used to using a qwerty keyboard.

Google's voice-recognition technology will be first available for the iPhone, even before devices, such as the G1, running its own Android mobile platform. Google will soon offer the technology for other devices, including the T-Mobile G1, which uses Android. Google also has a voice-search client for the BlackBerry, which, at the moment, is limited to maps.

But Google is playing catch-up. Yahoo and Microsoft already offer a voice-recognition option for mobile phones. Microsoft's Tellme and Yahoo's oneSearch both offer voice services.

I suppose the voice search will be most useful when a you might need to call directory assistance or do a simple search, but you can not do it safely, or legally, on a keyboard while driving. Especially here in South Africa where there can be hefty fines given for talking-and-driving. Another benefit might be the ability to search for potentially long queries that would be difficult to type.

But accuracy will still be a factor. What with all the different languages around. 11 official languages here in South Africa. What about all the different accents and word pronunciations. Apparently it works best with ‘North American’ accents. No surprises.

Google's voice recognition is far from perfect. Getting most searches right, but still inconsistent. The biggest let down, and perhaps not fully shown in the video released by Google, is the fact that you cannot search your contacts via voice. You still have to do a manual type search. But you can use a separate app available for the iPhone, "SayWho", which will dial your selected contact for you, using voice recognition.

Could voice recognition be the next killer app for mobile? The voice recognition market is growing at galloping pace. In 2006 voice recognition technology sales where in the region of $1 billion. That number is expected to swell to $2.6 billion by 2009.

What are your thoughts? Have you downloaded it yet? Have you used it? Has it worked?