You can get 1000 Free Hilton HHonors points by registering a mobile phone number and a Visa card. You’re basically agreeing to receive “special offers” via text. They promise to only send you two messages and you can opt out at any time.
You can earn an additional 4000 Hilton Honors points by spending at least $100 at a US Hilton hotel or resort with your registered Visa card.
You must register by June 30, 2012 to receive the sign up bonus and must spend $100 by then to receive the additional 4000.