Arachnia

Adium gives you plenty of ways to customize the way it looks and acts view it

Completely change the way Windows looks, feels, and acts view it

Set up your preferences and even change the way Wikipedia looks! view it

A look at Microsoft's latest, the Windows 7 beta view it

Windows Live Messenger allows you to customize a variety of options view it

Customize the way your Dock behaves view it

Here's how to change the boot order on your PC view it