I kind of wish more people realized how much of everyday computer usage can be simplified with keyboard shortcuts. Take a look around your favorite apps/programs and/or Google for “keyboard shortcuts”, and try to build a habit of using shortcuts for some of the most frequently used commands. It's very liberating as it gives you a feeling of greater control.

For example, in Windows, did you know that if you pin your most used apps on the taskbar, you can access them using Win+1, Win+2, etc.?

In browsers, you can press Ctrl+L for the location bar (URL) and Ctrl+K for the search box. Ctrl+Shift+T will restore your last closed tab if you closed it accidentally.

Menus can be accessed with Alt plus the underlined letter. The File menu is pretty much always Alt+F. Many dialogs have elements with underlined letters too. We should demand this on the Web as well, as it's kind of becoming a lost art with fewer and fewer people knowing about it. It only takes an accesskey attribute!