I bought an Apple Wirless Keyboard today. It uses Bluetooth to communcate and can so far as I know also be used with ordinary windows computers. First, I paired the keyboard with my iPad. This procedure is very simple. Switch on the keyboard and then go to the Bluetooth settings in the iPad. There, chose the Wireless Keyboard. The iPad will then display a code you have to enter in the keyboard for creating the first connection. Just enter the pin on the keyboard, even if there is no actual feedback when entering a number.
I really like the keyboard for typing. I think it is developed thoughtfully. So it allows very fast typing.
As the keyboard is somewhat unnatural for the touch-controlled iPad, it offers only a few extended usabilities like shortcuts. The only buttons working reliably are the brightness and the volume controls as well as the play/pause/forward/previous buttons. Don’t expect the keyboard to provide any further functionality as cmd-t for tab creation or refreshing in Safari! Furthermore, the Bluetooth connectivity uses a lot of battery.