I'd like to take a moment to recommend Screen Calipers. I'm a perfectionist when I'm working on custom interfaces, components and skins, so I use it all the time. It helps me check padding values, sizing, spacing, border widths, you name it. It's definitely worth the US$30.

What do you use to get things done, besides builder? I'm always looking for ways to improve my productivity and cut down on the boring parts of my day!