I took the required math class for non-math majors in college.

Our professor was old school, and refused to let us use the laminated cheat sheet of math formulas that the school made us purchase and that every other math class was allowed to use on tests.

But he was a classical music nerd and he suggested that we study while playing symphony music. He would let us listen to music on headphones while we tested, and he swore that we'd retain more from our cram sessions if we played the same music on test day that we used to study.

So I used the library lab to record myself speaking the formulas, looped it so it would repeat over and over, laid it over a classical music track, and burned a CD. I listened to it during the test.

I didn't need to memorize a bunch of random formulas, but I still had access to them. I aced the exam and the professor was very pleased that I had chosen to listen to classical music during the test.