With all the very cool podcasts out there now, I'm using my Zen to listen to those more than music most of the time. In fact, I've had to cut down my subscriptions because there is just too much to listen to.

Rich Sigfrit, one of the brains behind the Star Wars fan audio show Requiem of the Outcast, recently launched a new (non-SW) podcast and it's pure genius. Campfire Tales is a series of short recordings of Rich's wife's grandfather telling stories of the old days, just like your grandparents probably did: funny, sad, pointless, poignant, whatever. Its great stuff.

Other must-listens:
Tartanpodcast
Tom Corven by Paul Story
KnitCast