You might want to do some research on zigbee and xbee modules. They are wireless modules that run on their own protocol and they're pretty inexpensive. I think $21 USD for the cheapest module.
Still very cool to have a protable bluetooth printer, very inventive!
I can't wait to see your other creations :)
I could see this anchored to a wall and able to move both horizontal and vertical. Make it so anyone can connect to it and make it print something.
Would make an interesting mural :)