When I was surfing the web I came across this device.

http://www.youtube.com/watch?v=RTEKN1UO8cc
It is an easy way to make your fingerworks device wireless. I wonder how long the battery will last. It says it can go up to 120 mA.
Here are the features:
•Works with the following devices: iPhone/iPad, Android phones and tablets, Windows XP/7/8 laptops/tablets. Note you phone/tablet/pc must support Bluetooth keyboard. Many low-end phones do not. Currently the adapter does NOT work with Mac. Let us know if Mac support is really important to you.
•One PS/2 keyboard port supporting any PS/2 keyboard (max current 120mA)
•One USB host port supporting most standard USB HID Keyboards (max current 120mA)
•One mini USB port for battery charging
•1100mAh removable, rechargeable Li-ion battery
•Bluetooth 2.0 compliant
•Class 2 Bluetooth Wireless (10-meter distance)
•Charging LED, Status LED and Wireless LED
•More than 10 hours continuous use per one full charge (affected by the power consumption of the keyboard used)
•Mini USB cable is included. Wall charger is NOT included. You can use any standard USB charger or plug it into a PC to charge the battery.
Meesters