One of the things I really like is listening to podcasts on my iPod on the bus. So far I have sampled the following:
I started off with Instapundit.com - look for it on iTunes in the Podcast Directory, or go directly to the Instapundit blog. The podcasts are Instapundit and Dr Helen inviting various guests on their show to talk about some topics. The sound is quite good. I have found that some podcasts are really bad at adjusting the sound quality where there are more than one speaker, and especially where one speaker speaks really badly. The topics are interesting. Instapundit and Dr Helen are quite passive in the podcasts that I listened to. They might ask a pointed question or two but they really don't intrude much into the podcast.
I then also tried the Scientific America podcasts (3). I found them quite interesting. Once again the sound balance where many people are talking was well managed. One review on iTunes Podcast Directory pooh poohed it a bit. But if you are a person who really doesn't want to think too much these are really informative and interesting podcasts without requiring too much brain damage (always a bad idea first thing in the morning.)
Then I tried the Mac Observers Mac Geek Gab (also available from iTunes Podcast). I choose 2 episodes - one about what the iMac does for you, and the other about podcasting. I am sorry to say but these 2 episodes had the worst audio. What I mean is the audio adjustment for different speakers. When one of the guys spoke, he mumbled so much I had to turn the volume up, which then meant when the other guy spoke my eardrums were blasted. I lasted 2 minutes before switching it off. To be fair I will give it another whirl and try a more recent podcast. (I am ever hopeful that they would have told Mumbly Guy to leave, or sorted out their audio problems...)