Scott Yang's Playground

Via ReadWriteWeb: SocialHistory.js can detect what popular social networks your visitors have recently visited by (1) creating a small hiden iframe (2) populate the iframe with links to those social networks (3) check the colours of those links, as visited links will usually have a different colour. One of the most wicked hack I have seen this year and I can already think of a dozen evil modifications that you can do to this script.