Surf the net anonymously with Tor
Tor is a network of virtual tunnels that give you a very good level of anonymity, using Tor with privoxy and FoxTor for firefox gives you privacy at the touch of a button.
Firefox Add-ons for Web Developers
Advanced Web Development by AskApache is a Firefox Collection I created since I'm always trying new Addons out and using multiple computers and I wanted a quick and easy way to install my favorite's and keep a running list. Firebug, YSlow, LastPass, and Web Developer are the only ones I always use regularly.
I like the idea of the last.fm but it's not as powerful as the site, which is awesome. Lately listening to Kings of Leon Radio...