http://www.nuance.com/naturallyspeaking/ If you mean like a typing thing. There are lots of voice recognition software out there, but I assumed you meant for dictation. Dragon Naturally Speaking 8 was pretty good, they have 9 now and I don't know it's improvements upon 8, but in dragon 8 you set up the software to recognize your voice and speech pattern by reading paragraphs. It's amazingly accurate once you set it up, though it takes some time (30 minutes to an hour)
