This device, available at ThinkGeek — on sale for $99.99 — projects a laser onto a flat, opaque surface, and then allows you to actually type on it…complete with actual clicking sounds!
Some of the Product Specifications are Greek to me, so I’ll include them here, directly from ThinkGeek, unparaphrased:
Epic – Bluetooth Virtual Keyboard projects keyboard on any flat, opaque surface
Full-size QWERTY keyboard, full-size key pitch
Doubles as virtual multi-touch mouse
Connects via Bluetooth V3.0(class2), HID Profile Ver 1.0
Frequency Range: 2402-2480Mhz
Compatibility: iOS 4.0 and later, Android 4.0 and later, Windows XP and later, and Blackberry 10 (compatible with any Bluetooth HID supporting devices)
Recognition rate: 350 characters per minute
Light source: red laser diode (IEC Class 1 Laser)
Batteries: Lithium-ion 660 mAH (MAX) @ 3.7V (provides >2 hours of operating time)
Charges via micro USB cable (included)
Dimensions: 2.7″ high x 1.35″ long x .75″ wide, keyboard 3.9″ high x 9.4″ wide
Weight: 7 oz.
Note: Mirco USB cable is only for charging, not for making a connection to a device