TheCoreWithin

If you understand german, this is a fun podcast to listen to:
http://pod.drs.ch/satire_peter_schneider_mpx.xml
http://www.drs.ch/podcasting.html

If you are interested in computer security, SecurityNow is great. They talk about a lot of other stuff too (their sponsors :), but the content is great.
http://www.twit.tv/sn

If you want to learn japanese (I try since years, but well... no patience :)
http://www.japanesepod101.com/index.php

www.digg.com/podcasts/diggnation

and if you count vodcasts, the best thing on the internet right now, www.tikibartv.com