Hadn't seen this posted yet, so have at it - a choice!
"Choose one of the following options:
Earn up to three Free Weekend Nights.
Stay three times between June 1 and August 31, 2007, and get a Free Weekend Night (up to three nights free) when you register by July 15, 2007.
OR
Earn up to 18,000 bonus Starpoints.
Stay three times and earn 3,000 bonus StarpointsŪ, stay six times and earn 9,000 bonus Starpoints or stay nine times and earn 18,000 bonus Starpoints when you register by July 15, 2007, and stay between June 1 and August 31, 2007"
www.spg.com/promo
If this has already been posted, my apologies