Ebates is one of the cash back online shopping portals that I find to be reliable.
Today only (May 23, 2014), they are offering double their usual payout rate on travel purchases at Orbitz: up to 13 percent off travel bookings.
If you book a hotel stay, you can get and additional 15 percent discount with the coupon code: GETHAPPY.
Book by May 31, stay by November 15, 2013.
Check the Promos page for more Memorial Day weekend deals!