What you need: Rubber eraser, X-Acto Knife
Risk level: Medium
One of the most unassuming ways to bring your paper notes to an exam, the eraser method is relatively simple. Measure your paper note and mark two points on your eraser slightly larger than the note. Using the X-Acto Knife, cut out a portion as wide as the marks and as thin as half the eraser. Now, you can place the note into the erase, put the piece you cut out back on, and go about your day. Not very high-tech, but it's been known to work.