Here are the details:

To be eligible for this offer, you must
(1) select Delta Air Lines as your Double Dip® earnings partner in your Hilton HHonors™ account profile,
(2) register online at www.hhonors.com/moreskymiles before booking your first stay, and (3) complete a required stay (1 night, 2 nights, or 3+ nights) at a Hilton Worldwide portfolio hotel from January 3 through March 31, 2011. You must be a Hilton HHonors member to earn Points & Miles™ for hotel stays.

Delta Mileage: Earn up to 2,000 miles for a 3-night (or more) stay, up to 1,500 miles for a 2-night stay, and/or up to 1,000 miles for a 1-night stay. 400 miles for a 3-night (or more) stay, 300 miles for a 2-night stay, and/or 200 miles for a 1-night stay at Hampton Inn & Homewood Suites.

Miles are not eligible to earn Medallion Qualification Miles.

You can earn miles for multiple stays with this offer.

Allow up to six weeks after qualification, and after promotion has ended, for miles to be credited to your account.

This offer may be combined with other offers and/or promotions.

All SkyMiles program rules apply. To review the rules, please visit delta.com/skymiles. Hilton HHonors™ membership, earning of Points & Miles™ and redemption of Points are subject to HHonors Terms and Conditions. Other restrictions may apply.