Connecting to NXT Brick via Processing over Bluetooth
You can use any programming language you like to remotely control the NXT provided that it can access a serial port of your computer. The Bluetooth connection on the NXT provides a virtual serial port. You can see this by opening "Devices and  Printers" and double-clicking on the NXT (provided that you have already paired it). Then have a look at the "Services" tab in the window that opens.



In the screenshot above, my NXT provides a serial port on COM4. Yours may be a different number.

So you need to do two things:


Figure out how to open a COM port on Windows using the Processing programming language.
Use the information in the NXT Bluetooth Developer Kit (available from the LEGO MINDSTORMS download page) to send commands to your NXT.


To use other Bluetooth devices with your NXT, you will need to relay the information though a computer to translate it into the commands from the NXT Bluetooth Developer Kit. In the case of the iPhone, you could write a custom program just as you would for a regular computer.