Here's what I keep coming back to...
Deloitte Insights Podcast: A great discussion of corporate strategy from the folks at Deloitte. They had a great session on the Strategy Paradox back last February.
Feast of Fools - Gay Fun Show: I'm not sure how to describe this, except to say that Marc and Fausto are really, really funny, and you don't even have to be gay to appreciate this one.
MAKE Magazine: This is a video podcast, generally concerned with weird things you could make in a weekend. These guys sent a balloon up to near-space to get some pictures. They never recovered it, but it's pretty cool that people try stuff like that.
NOVA Vodcast: A great videocast for science geeks.
NPR Car Talk call of the week: I only wish Click and Clack would make their whole show available by podcast. This is sort of a teaser, but it's worth the download.
NPR Wait, Wait--Don't Tell Me: NPR's hilarious weekly news quiz show. The whole show is podcast, and their guests are great.
Pop!Tech Pop!Cast: This videocast series broadcasts GREAT lectures from really smart people. The April 8th episode featured Thomas Friedman on the subject of the current energy crisis.
The CNN Daily: A well-made videocast that catches me up on daily news highlights.
More to come as I discover them...