Between April 1 and June 30, you will receive double Hilton HHonors points on all stays. Also, if you are a mileage earner with your double dipping, you can instead opt for double miles when credited to your frequent flyer account.
While this promotion is nothing to write home about, it is still something. It also starts right after the 1st quarter promotion ends, so I am happy that there is no break in promotions.
You must register prior to your stay and select the double points or miles option first. Remember to chose carefully as you will not be able to change your selection! You can register here.
Like always, there is a decently long list of hotels that are not participating in the promotion, mainly in the US.