This seems like a useful tool when I’m interesting in an article that’s a bit outside my sphere but want to find similar sources of information, commentary, etc. Similicio.us, at http://similicio.us/, takes articles you specify and finds what folks who linked to that article on Del.icio.us also linked to.
For my test run of the site I tried the article The People Formerly Known as the Audience. When I plugged that in to Similicio.us, I got a list of sites that was somewhat journalist-oriented — CyberJournalist, Poytner — with some general news sites and blogs thrown in. When I tried to get do a link:http://journalism.nyu.edu/pubzone/weblogs/pressthink/2006/06/27/ppl_frmr.html at Google, I got NO results (yikes!), while a link search at Technorati found 20 posts over the last four days, sorted by freshness and containing a few duplicates.
Actually I didn’t find much overlap between the Technorati and the Similicio.us results. They might be good tools to use in conjunction with each other…