An Omnichord is an electronic musical instrument, introduced in 1981 and manufactured by the Suzuki Musical Instrument Corporation. It typically features a touch plate, and buttons for major, minor, and diminished chords. The most basic method of playing the instrument is to press the chord buttons and swipe the touch plate with a finger or guitar pick in imitation of strumming a stringed instrument. (SonicCouture)
SonicCouture Omnichord costs 5 EUR (US dollars / UK Pounds), it's available until 31st April 2011, and 100% of all payments will be donated to the Red Cross Japanese Tsunami appeal.
Audio demo: (credit goes to official website)
More info: SonicCouture Omnichord