It looks like Nuance will have two iPhone hits in one month. Dragon Search [iTunes link] has just gone live on the App Store for the iPhone.
Using the same technology that's in Dragon Dictation for the iPhone, Dragon Search allows you to speak your search terms into the iPhone and get hits from the web including iTunes, Twitter, Wikipedia, YouTube, and Google. You can also add Yahoo and Bing to the searchable universe.
I've tried it and it works well. You want to be in a fairly quiet place for the best results, but it worked fine in a noisy car and in a moderately loud restaurant.
As with Dragon Dictation, your query goes to a Nuance server and comes back to the app in a couple of seconds. If you want to search beyond Google, this is a great way to do it. Speed is very good on a 3G connection, and of course it works over Wi-Fi and the EDGE network.
The iTunes integration is quite nice. Say 'Harold Budd', for example, and click the iTunes icon and you'll see what the iTunes store has to sell. Or you can search Wikipedia or Google and learn all about him.
The app is free for now, but not free forever, so if you want it, get it ASAP. It's yet another reason to love your iPhone.
The app requires an iPhone and OS version 3.1 or better.