Thanks so much for doing mp3! It made me so happy that I signed up for the radio club. I should have signed up long ago... I've been a freeloader for years. But better late than never, I guess. :)

One suggestion I have. Ask Catholic Answers to make MP3 CD's available in even higher quality.
Do this bi monthly or quarterly.
Use a gift-donation program to obtain these higher quality MP3 CDs, it will encourage gift giving to Catholic Answers, will make higher quality MP3 CDs available (better quality then on the web) with NO download time, and would be a nice tool for evangelization (with the usual copy permissions conditions from CA).
By continuing to offer the FREE downloads too, nobody can complain, while CA can raise always-needed revenue.
Just a suggestion.

It helps with size if you reduce the bitrate. It generally doesn't sound noticably worse (if you aren't doing music - I listen to CAL normally on AM radio at the edge of reception and the worst MP3's are better than that). I usually use 24kbps mono and it sounds clear. I also use iTunes with audiobooks or CDs conversion with this.
On my Mac, I have a product called Audio Hijak Pro which can intercept sound, so I have used it to record (yes, from webcasts - it can work like a VCR) or convert to MP3s. Instant podcast.
I think "Total Recorder" does something similar under Windows.

Podcasts! I have to second Jeff's post. I just discovered these and am already addicted to Catholic Insider and Vatican Radio. Please consider this for CA Live.

That's great news. I've been on the edge of my seat waiting for CAL to be offered in .mp3 format. Hope it comes out before the end of the summer.

I hope your long-term plans include an iTunes podcast via RSS! That would make it very easy for many people to find and listen to your podcast, and add more Catholic content (besides Vatican Radio, Catholic Insider and a few other smaller podcasts) to iTunes ever-expanding list.
But simple MP3s would still be an improvement :-)

Are y'all going to have capable servers and bandwidth to host CAL in mp3? Now that I have an mp3-capable stereo in my car, I'd like to do a wget -r on each month or year (get every show), and never have a dull moment in the car again. But I wouldn't want to do that if it would help pound the servers into the ground.
Maybe you could do "THE COMPLETE CA LIVE: YEAR XXXX" via Bit Torrent. :)