With further thought, the RSS feed is what I'd like to see as a "click hre to share" thingie. I use RSS on other sites; it could be a great way to showcase the diversity of Mudcat discussion, the MUSIC focus of the site, and (because of the creativity of titling variations) a sense of the real personality of the place.
It's like a very-portable brochure, and if the BS section was something people had to earn their way into (Members-only, probationary periods, etc.), the RSS feed would be a very strong draw to the upside of the Cat.