Was poking around at looking for chord charting software and I found this tool. It's not free but I probably will pay for it and it's cross platform (that means PC and Mac to you non geeks
). It basically lets you figure out the chords or notes of an audio file by selecting a part of the wavefrom. It analyzes the waveform and lists the individual notes in the selected part of the waveform. It can also do the slowdown thing.
I took Robs AngelsShadow file and was able to pick out most of the note to the 1st A chord it then told me where those notes were on my 6 string bass fretboard.
http://www.seventhstring.com/xscribe/overview.html