Unfortunately, there's no consumer software out there yet that'll transcribe audio in a way that's useful for interviewing – no separation of speakers, word recognition is iffy under great conditions, awful under standard (crazy google voice transcripts anyone?), rough use of punctuation, and so on.
What DO exist, and they are super useful, are programs that will allow you to pause, repeat, skip around, etc while typing in the conversation, allowing you to go through the whole process without lifting your hands from the keyboard, a major time saver when you're dealing with multiple hour conversations. There are even free web apps available (I haven't used the one linked, but it looks decent). For serious transcription work, software based around foot pedals is available to offload the repetitive tasks from your hands, speeding up the process even more!
(Oh God I hope I never get to the point where I'm transcribing enough interviews to be searching for foot pedals. It's drudgery.)
So yeah, huge thanks for doing this, triverse, sounds like it was a ton of work.