International Flight, 13-hour layover in Beijing on 27 Dec 2012, do I need a visa?

I am travelling from Australia to the USA on the 27th December 2012, and have a 13-hour layover in Beijing (Capital International Airport). If I exit the airport to stay at a hotel (the layover is overnight), do I require a transit visa? Alternatively, is there a hotel at Capital Intl. which is WITHIN the airport boundary and/or transit area?