Ian@FalsePositives.com writes "Technorati (a search engine for blogs) has a new 'tag' service. If your blog tool of choice uses Categories, has a RSS/Atom feed, and pings technorati, then you're done. If not, you can add tags via a new tag markup. The twist is that Technorati is working with Del.icio.us (a social/sharing bookmark manager website) and Flickr (a social/sharing photo web site) to read their tagged content! So Flickr pictures, Del.Ico.us bookmarks, and blog posts all on one page! Here's an example result for the tag Toronto. There is some documentation as well. One current limitation is that there is no way to do tag intersection as with del.icio.us (i.e. http://del.icio.us/tag/toronto+food ) like http://www.technorati.com/tag/toronto+Food. Tagging (also know as Folksonomies) was the topic recently on Slashdot: Folksonomies In Del.icio.us and Flickr."