A linked history of viral marketing campaigns

Blogger Rex Sorgatz recently did a commentary about viral marketing campaigns, for the public radio show "Weekend America." As a supplement to the commentary, he also put up a page full of links to past viral campaigns still on the web, agencies who create such campaigns, and other practical resources. It's the most comprehensive central page of links I've come across yet, and I'd encourage you to check it out if you're interested in actually interacting with some of these past campaigns. Mr. Sorgatz has a great line in that entry, by the way, about what it's like to actually watch some of these campaigns unfold: "Sometimes it's strangely addicting, and other times it's like watching your parents dance to Outkast." (Thanks to Site-9 for pointing this out.)