Great listing of Web 2.0 apps that let you spy on yourself ...

Stalking 2.0: The Websites that Track Your Every Move (Voluntarily!)

So, you don’t mind being followed and tracked? You don’t care if your friends can see what websites you’ve been to lately, what software you’ve been running, or even what music you’ve been listening to? Then you’ll love the web’s trend towards extreme openness: sharing everything you do on your computer. Sometimes referred to as sharing your ‘attention’ data, this is a growing market. Below, we round up 12 services that want to track your every move - voluntarily.