Another Dr Karl vote from me. I listen to his BBC5Live phone-in, and the Naked Scientists one, though it's worth pointing out that there are two - "Dr Karl and the Naked Scientists" which is a couple of weeks of Dr Karl's show and then a week where the podcast is a segment from the full Naked Scientist one. Of course there's the full "The Naked Scientists Naked Science Podcast" too, which I prefer to the snippits on the BBC feed. They also do Naked Archaeology which is quite good if you like that sort of thing, though doesn't feature the most charismatic professors. Their Naked Cosmology one was awful because the professors were dull. Only listened to one or two though.
A comedy one that's okay for the odd bit of general knowledge and nonsense is "Answer Me This". A trio of students who are a bit posh answer whatever questions their listeners send in, by googling and then talking about it. It's good background chatter with the odd tidbit of interesting info.
For shorter podcasts with a sceptical science base, "Skeptoid" is one of many good ones.
"If you can't look a knob in the face, there's something wrong with you."
Chicanubelieveit wroted: "I think kate mckay may well be some sort of sex kitten who oozes sophistication as she walks into any room."