It might turn out to be the worst year in recent memory for the PR industry, but there has been great progress in the use of social media to reach various constituencies. From Skittles' experiment, whereby the company turned over its homepage to a running search of Skittles references on Twitter and employed various other social networking curios, to eBay's decision to live blog its recent analyst day via Twitter, companies are finding groundbreaking ways to use Web 2.0 properties ...