PCB rulers — literally rulers made out of printed circuit boards — are an ingeniously nerdy idea. They are thick and stiff enough to make them useful as a straight edge, and the silk screen of the PCB is used to bring charts and tables to the party. You could design your own, or find them for sale on Tindie, Adafruit, the SV1AFN Design Lab, or many other places. We’ve even done a list of PCB rulers if you need more ideas.
Though they normally contain useful visual elements, for the most part these rulers are passive devices. For something a bit more interactive, may I present the Digirule. This device not only features length measurement in a binary format, but contains logic gates, flip flops, a counter, and 9 Easter egg modes as shown at 2:45 in the video below. Perhaps it won’t help you get more work done, but it looks like a really fun distraction, and the different logic functions could be a really useful learning tool!