What are some good open source speech to text programs?

What I'd really like is some sort of program that would allow you to take a .wav file and convert it to text instead of just being able to record via microphone in real time. I know Microsoft Office has some sort of speech recognition software, but I don't use Microsoft Office, I use Open Office. So I'd prefer an open source or free ware speech to text program, but if you don't know of any and can point me to one that is pretty cheap I might go that route. Thanks for the help.