Ways to Go Wireless Arduino

Link for in-class reference.
http://www.sparkfun.com/search/results?term=wireless+arduino&what=products
Also
http://www.makershed.com/Wireless_Sensor_Node_Receiver_Shield_Bundle_p/msbun29.htm
http://asynclabs.com/store?page=shop.product_details&flypage=flypage.tpl&product_id=29&category_id=6