Ever get confused about all the security settings on social networks? If so, here's a simple fix (if you're on Chrome or Firefox, that is). After installation, Privacyfix will scan your profiles and show you how you've got your profiles set up, and what you can change to make them even more secure. It even takes you directly to the right configuration page. No excuse now.
Firefox has a neat little addon called Tilt that enables you to visualise any site in 3D. Look at Mashable. It's pretty cool. I'm sure it's also very useful for people who are in to that kind of thing. Apparently it's useful "when searching problems in the HTML structure (like finding unclosed DIV elements for example) by providing the extra third dimension, layering each node based on nesting in the DOM tree." I just think it looks cool.
Check out more in the video.