OLEDs
OLEDs are quirky, but they can be used for some pretty cool stuff. Some keyboards allow you to add OLED screens to them in order to really put your keyboard over the top. OLEDs can be programmed to display your current layer and keypresses, real-time WPM charts, an 8-bit picture of anything you can think of, or even little animations. One of the cutest we've seen was a little kitten that acted more and more excited as you typed faster.