Geek-lights are the indicator lights embedded on the surface of your electrical equipment. The green "On" light. The blinking light on your ethernet port or USB thumb-drive telling you data is being transferred. Most of them tell you redundant or otherwise obvious facts. I don't need an "on" light for the monitor I am using. It is useful information when in power saving mode, however. Apple seems to have learned this.
However, geek-lights are incredibly useful for other kinds of information. Information that is different for you and me. For example, one to indicate if traffic is too heavy to venture out now. Another to tell me that I have email. Another to tell others that I am in a conference call and not just talking to myself again.
I would like to have a box of these geek-lights that I can use each for a specific purpose. The geek-light would be nothing more than a shallow and wide cylinder with the light on the top, temporary adhesive on the bottom, and the electronics sandwiched in between. Let's call them eyelets as they let you see something ordinarily invisible. Each eyelet is individually addressable by a short range wireless signal. An eyelet receives a signal that indicates whether it is illuminated or not. Eyelets don't send signals back. I can imagine the hardware being something akin to Logitech's Unifying receiver -- that is, unobtrusive.
The question now is, should eyelets have a battery charge indicator light?