This deal has ended.
Update: This is back on! Starpoints are practically worth their weight in gold and you can currently get up to 25,000 free by signing up for the American Express Starwood Card. Starwood, the parent company of Westin, W Hotels, St. Regis, Le Meridien, Sheraton and more, has a very generous rewards program (see exactly how generous). With little effort, I just personally booked a $350 hotel room for 4,000 points plus $60 in cash per night, meaning the points were worth about $0.07 each, far better than the penny-per-dollar you'd get from a cash back card. Also, the Starwood is free for the first year (normally $65) and has a low 2.9% introductory APR for 6 months. Plus, there are many AmEx Starwood benefits.