Since I just bought an iPhone, I'm using iTunes more often now (my iPod sat, unused, in my briefcase for quite some time). Subscribe to the resulting feed in iTunes, and voila! Now any MP3 file you guys tag gets routed to my iPhone.
I'll report back with any particularly good finds you guys steer my way.
Update: In the comments, Eric points out that I'm standing on the shoulders of a few giants (namely, Eric, Fred and David Hornik) by re-purposing this. I'd completely forgotten the origin of this idea - and enjoyed re-reading the original post that planted the seed for me. I also like the more modern implementation - Sam's idea to redo this as a Twitter-powered podcast. Neat!