I understand you dilemma -- I've done live shows in the past (and actually just started contributing to another one last week) and getting the timing right can be tough.

If I could offer any advice, it would be to consider Sunday evenings. I know you have to be at work at 4 AM, which totally puts you at a limited time to start -- but I know that when I worked for TUAW, the participation we had week after week on Sunday nights at 10 pm Eastern always blew my mind. And I know that the shows on Talkshoe before us at 9 often did well too. Weekend afternoons can be just like weekday nights -- but for whatever reason, Sunday evening seems to be a decent time for people to tune in. Or maybe at TUAW we were just really, really lucky.