Speech to Text Software: Dragon Naturally Speaking

Requires very minor clean up but handles 300 wpm. Runs on PC, iPhone and Blackberry.
Mac Dictate for Mac OS.

http://www.nuance.com/naturallyspeaking/

For Mac OS, Mac Dictate - $199.99:
http://www.nuance.com/naturallyspeaking/products/macintosh/for-the-mac.asp

For iPhone - $349.99:
http://www.nuance.com/naturallyspeaking/products/macintosh/scribe.asp