The NailO is a thumbnail-mounted trackpad that can be controlled by your index finger. Developed by researchers at the MIT Media Lab, this miniature device somehow packs a battery, capacitive sensors, a microcontroller, Bluetooth radio chip and a capacitive sensing chip. In terms of appearance, it is inspired by the decorative nail stickers worn by many Asian women.
To use the NailO, users power it up by maintaining finger contact with it for two or three seconds. They can then move their index finger around its surface, which causes a mouse cursor to be moved around on a paired computer. To select or click on something, you simply press your finger down on the trackpad.
This device is no mere gimmick and has interesting applications. The fact that it can be used while simultaneously engaging in hands-full activities is what gives it its unique functinoality. It could also be used to access smartphone functions or send text messages in situations where whipping out a phone is not possible or appropriate.