Not certain it will work for you, but Sparkfun offers several wireless modules that look pretty cool (Note, be sure to look at both pages of wireless modules, many of the cheapest & most interesting modules are on the second page.). Their 2.4Ghz transceiver gives you 250Kbps with a range of up to 280 meters. It's not a replacement for USB, but if you just need to talk to the remote board, it might be a good option. If nothing else, you could likely use two Arduino's with the wireless link between them. If you do try this & it works, please post back here with a report!
i am thinking of using the bluetooth cable free system. the one that is for serial only.
but since i already have a board with a usb connection, is there any way to attach a serial port onto the board somewhere so i dont have to buy i new board?