Starwood has added a bonus mile promotion on top of its current free weekend night promotion. We wrote about the free weekend night earlier, but to refresh your memory: SPG guests can earn one free weekend night for every two stays completed between May 1 and July 31, 2009. Free nights can be redeemed through Sept. 30, 2009 without blackout dates, but not all properties are available.

Now, SPG is offering 1,000 bonus Northwest or Delta miles for stays at participating Starwood hotels in the Americas through July 31, 2009. The bonus mile offer can be combined with the free weekend night offer so you can earn bonus miles and free nights at the same time. Members must register for the bonus miles promotion and choose either WorldPerks or SkyMiles as your earning preference. And remember, you can easily transfer miles between your SkyMiles and WorldPerks accounts at no charge until the two programs combine into one.

Over 300 properties are participating in the bonus mile offer and you have until July 31 to register for the promotion with no limit to the number of bonus miles you can earn. Visit http://insideflyerus.wpengine.com/link/?1626 for full information.