Henry
Autoexreginated
En-un-ci-ate.
Make a test run before recording an actual session. Replay it in front of everyone. Then you can adjust the microphone(s) and berate the people who slur and mumble.
Best advice on the whole page, in my opinion. I've tried listening to many Live Play podcasts, and lack of being able to hear the players clearly is my number 2 pet peeve, and why I only listen to a very few.
My Greatest Pet Peeve? EDIT. Truncate. Skip to the good parts. I've seen some that record every blow-by-blow, including people rifling through papers, going to the bathroom, waiting for rules questions, YUCK!
If you want a good example, the Penny Arcade Podcasts and D&D Robot chicken writer podcasts are good examples of Live Play 'casts, which keep it fun and entertaining to listen to.