I've started one. But I stopped it after about a minute. They just take too much time. I'm busy - *always* busy - and the problem with podcasts is that they're spoken.
I want to be able to absorb data at my own rate. Usually that will be far faster than spoken. Occasionally I'll find something I want to poke at mentally a bit longer, and then, hey, I want to slow down and mull. Sometimes I want to look back a paragraph or two and read something over again. Podcasts don't give those options.
Aside from the "I can listen to this on my iPod!" factor, I really don't see the advantage. And I don't have an iPod. So.