heh ... I posted in an share-your-ideas last week about making a site that agragates the agregation sites and it seems that's just what picurls.com is all about. Taking the pictures from other sites like digg, readdit, del.icio.us and puting it all toghether. I think this can be done not only for pictures but for other things like videos, news, other-niches-categories.
It describes how I created picurls.com from scratch and I released the full source code of picurls.com! (Perl and PHP)