If you’re still using a basic ruler–the kind that’s a stick with notches on it–allow us to introduce you to the future, where our rulers will be crazy interactive devices that measure the angles on hand-drawn triangles and allow us to create our own Plinko games on the backs of receipts.
Glassified, a project from the MIT Media Lab, is a ruler with a transparent screen on one end. A camera in the ruler can pick up on lines drawn on a sheet of paper, and the ruler can project light that interacts with those lines. That can can make for a fun game, or be used to track more complex measurements (the ruler can apparently measure the angles on a hand-drawn triangle).
Oh, and all the lines you draw will be so straight.