Speech Recognition on iPhone

I need to develop an iPhone application which recognizes speech, and based on the result it performs further tasks.

I know iPhone 3.0 doesn't support speech recognition and I need to implement speech recognition software on the server side. I know this thing only, since I am newbie I don't know how to deal with that.

Mean Which software i need to buy and implement it at server side, and how to use that Service ??

The best open source speech recognition package I know of is Sphinx.
http://cmusphinx.sourceforge.net/

Otherwise, I would suggest looking into Nuance software.

Current speech recognition does well with a limited grammar set (if you know what they are going to say). Open dictation still doesn't quite work well enough to be used reliably for many applications. Keep that in mind while developing your application. I'm hoping now that Google is getting into the transcription game (with Google Voice) that should start improving. I'm thinking they will probably have something in the future.

I don't think there are many server side speech recognition software suites. Open source versions seem virtually non-existent. You might want to take a look at this SDK though:

http://www.scribd.com/doc/17247334/Creaceed-Releases-iPhone-Speech-Recognition-SDK http://www.creaceed.com/weblog/ceedvocalsdk.html

It might allow you to do what you want on the iPhone itself.

Getting speech recognition right is very tricky and an active research area.

There are a few open-source solutions out there, though, see here. An additional, new one is SCARF, but I don't know if that is ready to use or rather just a proof of concept.