The Hilton Honors program also gives you extra points for your rental car. You have to remember to show your rental car keys when you check in. Look into getting a hotel affiliated credit card. There is usually no annual fee for the Hilton Visa or AMEX.
We have found that hotel points have become very valuable to us. We can usually find a good flight price but then find hotel prices to be $200-400 a night overseas. Being able to use points for a free two week stay in an expensive city is real a bonus, in my opinion.