I want to make a geek ruler.This ruler should include common package, trace width, button battery, led. buzzer. Anyone who want to test components whether breakover, he just need to put it on the pad and judge the sound. Also he can use this ruler as a flashlight. Please give me some more useful ideas
DigiKey has a ruler. See DigiKey part "PCB-RULER-ND". It's a PC board with examples of most of the common component footprints and some useful engineering data for PC board design. If you order enough stuff from DigiKey they send you one free. Otherwise it's US$4.95.