The OP-1, shortcut for operator-1, is a portable synthesizer and controller.
Made by Teenage Engineering: www.teenageengineering.com
It has allot of sound engines, sample engines and many ways to add effects. It has also some funny stuff like motion sensors, you can add effect with this just by moving the op-1 around. The OP-1 also has a built-in FM, so you can sample direct from any radiostation or record. It looks very playfull n stuff, just like a toy.
Check it out yourself on: Teenageengineering.com