This “trackback” feature seems like the ticket for spreading the interactivity of the Weblog.  To be notified when someone has commented on your blog is a powerful feature for enhancing dialogue,  I would think.   From RadioFree Blogistan

“Both Radio and MT have a built in option for pinging Weblogs.com to announce when you have posted a new article. Movable Type also now features Track Back which enables you to ping a blog when you are commenting on it in your own blog and, likewise, enables you to show excerpts from blogs that have pinged you when commenting on your posts. This feature is a step in the right direction towards the greater weaving together of the blogosphere, permitting more easy navigation back and forth between intercommunicating blogs.“

Anybody know of Radio features or add-ons or scripts that allow/enable this feature?  I’m gonna do some searching in the Radio discussion area