I've been reading some GNOME 3 design documents recently and while I'm trying to build some kind of analysis out of it, it's the end of the semester and I've put the project on hold. In the meantime, please enjoy these two utilities! [Edited with smaller images]
It's not quite a program, but it's very useful if you spend most of your days in front of a computer screen. It's the Terminus font. It is, according to the project page, "designed for long (8+ hours per day) work with computers". I believe them. It is now my favorite monospace font and I use it wherever I need monospace fonts: consoles, code editors... name it! Here are a couple of screenshots:
Have you ever worked with a HP calculator? If so, then you are probably familiar the Reverse Polish notation. It is a way of entering mathematical equations that, in most cases, makes parentheses obsolete (making equations faster to input with less keystrokes). It is a bit weird to work with in the beginning, but when you get used to it, there's no going back. I've been looking for a RPN-capable calculator for some time and I found galculator. It's simple and fast - probably not as comprehensive as your 200$ graphic calculator, but it sure gets the job done! Here's a screenshot:
I hope you enjoy these two tools - they may not be as "life-changing" as desktop environments, but they sure make it easier!