[development] Best way to let a user notify other users about a new node they created?

Hi, list, I'm running a Drupal-powered social news site and want to give my users some tools to promote their submissions. Right now I'm using the excellent Tweet module to let them tweet out their stories after they go on the site, but I'd like to have something that would notify other users on my site of the new node, preferably with an e-mail. Digg's got a feature like this called "Shout." Are there any existing modules in Drupal that do this or approximate it? How else could I better arm my users to promote their content to other users and across the web. Thanks -Brad P.S. I'm running a D5 site with Drigg as the core of the social news piece. I'm also using Buddylist for social networking features.