Repeaters

Would this work as a repeater/range expander for a G wireless network…
http://www.bestbuy.com/site/olspage.jsp?skuId=6683314&type=product&id=1083711426745

Is this a good idea? I herd it was hard to install. I herd it has an Ethernet Port on it. Does anyone know if I could buy this and use it as a gaming adapter for an X-Box 360.