I love to listen to the radio while I write. Since most of the time live radio is *ahem* fucking awful, I listen to a lot of music on napster (which I've plugged before), the Tony Bruno sportstalk show, currently on Sporting News Radio (it isn't broadcast locally but Tony is so freaking funny I pay 5 bucks a month for the ability to stream the show) and lately podcasts.
I like podcasts because there are some great ones out there by gamers and for gamers.
My three favorites (in no particular order- every one of these is consistently worth a listen):
Does my geek look big in this: A British couple who talk about beer (!), games and movies. They are huge Firefly/Serenity fans as well. A big plus. This one has to be my favorite of the lot.
Have games will travel: A really nice low-key podcast by freelancer Paul Tevis. He interviews freelancers, talks with great knowledge about game design and the industry (a huge, refreshing plus for me since by visiting message boards I am confronted by thousands of folks who know nothing about either one- though expound with great authority- daily).
Dragon's Landing: The longest running podcast of geekdom that I know of. Chuck and Lonnie have really good insights into gaming.