Windows only: Learning through repetition is a proven method for learning new information. Freeware application Memoriser brings that repetition to the screen you stare at all day with a digital approach to flash cards.
Memoriser pops up questions at predetermined intervals while you use your computer to quiz you on whatever you're trying to memorize. Similar to previously mentioned Mac-only flash card application Genius, Memoriser tracks the questions you get wrong and quizzes you more often on the ones you have the most trouble with.
Questions can be grouped into categories and each question can be individually toggled on or off. The one-at-a-time method of entering questions can be a bit slow, but you can hand-edit the questions.ini file in the Memoriser install folder if you feel comfortable with plain text. Memoriser is freeware, Windows only.
Let us know your best tricks for getting the stuff you need to know into your brain in the comments.