A plugin or code that groups related posts like Google news does?

I have an RSS Wp-o-matic blog that works great but it would be really great if it were intuitive about grouping related stories just like Google news does, so you’d have a better idea of what the main stories are and not see multiple sources covering the same story … any ideas?

Google does this using some crazy algorithm I’m sure but maybe there is someone smart out there who has done something similar with WP or could figure this out in the future?