Birdman, I downloaded this free audio converter to convert WAVs to MP3s. It's quite simple to use, and you can "batch convert" multiple files. The formats it handles are M4A, MP3, AAC, WAV, WMA, OGG, FLAC, and APE (snicker - wonder what that format does). It uses the popular "Lame" MP3 encoder during file conversion. The four different MP3 settings it uses are:

"Lame insane quality" - 320 kbps, 48khz, joint stereo
"Lame extreme quality" - variable bit rate, 48 khz, joint stereo
"Lame standard quality" - variable bit rate, 48 khz, joint stereo
"Old standard" - 192 kbps, 48 khz, stereo

Just for shits n' giggles, I tried all four settings on your "bird rant 2 coal.wav" file, originally a 59.7 MB file at 705 kbps /11:50, and the results were:

"Lame insane quality" - 320 kbps, 27.0 MB
"Lame extreme quality" - vbr, avg. 192 kbps - 9.78 MB
"Lame standard quality" - vbr, avg. 192 kbps - 8.41 MB
"Old standard - 192 kbps - 16.2 MB

Average file conversion time was 45 seconds for a 12 minute WAV file. As you can see, the file size shrunk by anywhere from 32.7 MB (using the "insane quality" setting) to 51.29 MB (using the "standard quality" setting), while maintaining nearly identical audio quality. For "vocal performances" such as your rants, the standard quality setting should provide more-than-sufficient results.

Here's where I downoloaded it from:
http://www.dvdvideosoft.com/products/dvd/Free-Audio-Converter.htm

Now of course with it being freeware it might be more of a pain in the ass than it's worth, as it does ask you if you want to install a DVDVideoSoft Toolbar for Internet Explorer or Firefox, Set the DVDVideoSoft Search as your default search engine, and set the DVDVideoSoft web search as your home page upon initial installation, and every time you exit out of it. I just uncheck the checkboxes and move on. There are a host of other free converters out there via a quick Google search, some probably better than this one, but this one was the first one I tried, and it seemed simple enough to me to convert a few WAV files. It doesn't do "normalization" to smooth out the quiet and loud parts, unfortunately. Audacity, as others have mentioned, is decent, and free, as well. For a truly do-it-all program, I'd recommend Adobe Audition. It'll do almost anything, but it isn't freeware. It has a bit of a learning curve as well, but not as bad as other Adobe apps.

By the way, I love the rants. And I'm waitin' for new epsiodes of Chimpout Radio, UK Darkie Destroyer, and also lookin' forward to the Ladies' Show.