hey guys,

i have a question about the xbee modules,  How can we connect it to the computer (the one that acts as a transmitter). Use  xbee + xbee Shield + Arduino or just xbee + USB adaptor?
and in either case the PC will act as the controller, right?

thanks in advance

Just xbee + USB adaptor is enough for PC to communicate to Xbee.

http://diydrones.com/profiles/blogs/announcing-the-3dr-radio-telemetry-system

Wow, these are good and affordable!

Are you looking for these:-

Xbee USB adaptor
http://shop.sumeetinstruments.com/index.php?route=product/product&path=41&product_id=124

Xbee products
http://shop.sumeetinstruments.com/index.php?route=product/category&path=41

Yes, no micro-controller is required for the USB board. you can communicate and set properties of the xbee module using the X-CTU software. On the arduino/other microcontroller you may use the SIP adaptor or Xbee adaptor on breadboard or prototype board.