Thanks Tim for reminding me of the Oblique Strategies card decks. I am tempted to try to pick up a set--they are wonderful collections--but it'd probably be a lot easier to simply create my own from the text listings on the site.
Eno and Schmidt used the Oblique Strategy cards in collaborating on Eno's classic 1977 album Before and After Science. (Before and After Science is one of four stupendous albums that Eno made in a row before abandoning--for a while--vocal "pop" music in favor of soundscapes. Before and After Science is my second favorite, behind Taking Tiger Mountain By Strategy).
Some of the cards are strictly constrained to recording an album ("feedback recordings into an acoustic situation") but others are applicable to any circumstance: "Emphasize differences," "emphasize repetitions," and "emphasize the flaws." Or, "listen to the quiet voice."
I can imagine randomly pulling an Oblique Strategies card to help us look at things in a different way on an agile project. They could act as effective tools for keeping retrospectives (and perhaps other events) lively. Some of the cards are quite interesting when you think about both their musical application and adaption in a software development process: "Look closely at the most embarrassing details and amplify them." In a fashion, that is what the lean concept of "stop the line" is about.
What might you do with "Take away the elements in order of apparent non-importance?"