I never really saw the point of podcasts up until very recently. I kind of saw them as always outdated amateur radio shows. But I've actually started listening to a few now and I quite like it. So here's some of the geeky stuff I've got on my iPod.
Audible Ajax
Lots of web talk and trends. From the guys at ajaxian.com.
Jeff and Casey
Two game developers that talk about musicals, cars, microsoft and internet porn. It's funny and silly.
Pragmatic Podcast
Software development from Pragmatic Programmers with lots of interviews.
StackOverflow
Jeff Atwood and Joel Spolsky creates a programming community and talks about it and lots of other things.
Software Engineering Radio
Pretty hard core computer sciency stuff.
TEDTalks
Brilliant and random talks about technology, entertainment and design.