Recorded Speech to Text Software?

shfted! asks: "Recently, I've been given the task of transcribing several dozen audio tapes of interviews to typed word, that is, listening for 10 seconds, write what was said, repeat. At around 4 hours per hour long tape, I would like to automate the process somehow. Recording the tape into the computer is no problem, but I need some software that will do the speech recognition accurately more than quickly -- several hours per tape is not an issue (I have access to several machines running 24/7). I will still have to go over the computer's work to correct any mistakes. A free solution for Linux would be best, non-free and Windows solutions are okay, but a working solution is highest priority. Can anyone point me in the right direction(s)?"