Can I book a flight using my AMEX Gold card and then cancel the card before I travel?

i decided to open this card because they offered a free flight and no annual fee for the first year. my first year will be up in september 2010. i would like to book the free flight before sept to travel in jan 2011 and then cancel the card right away after i book it to avoid being charged $150 for the new year. would i be able to cancel the card with a flight still coming up? due to prior travel plans i cannot take an another trip any earlier than jan 2011.