The Levelator from The Conversations Network
http://www.conversationsnetwork.org/levelator
"It's software that runs on Windows, OS X (universal binary), or Linux (Ubuntu) that adjusts the audio levels within your podcast or other audio file for variations from one speaker to the next, for example."
Samuel Bayer: Mike, Dammit
http://www.sambayer.com/whymike.html
"it seemed to me that there was probably an awfully good argument against "mic", and since I happen to have a Ph.D. in linguistics, I thought I'd finally try to put my stake through the heart of this particular beast."
betterrec
http://betterec.sourceforge.net
"I wrote this program because I noticed that my PalmOS device (LifeDrive) contains quite a good hardware for recording sound, but (surprisingly) there was no good software which could fully use its potential."