Southwest Airlines Rapid Rewards members will get up to 40 percent off plus triple credit through Aug. 31, 2007, on all Budget rentals of three or more days. You’ll get 1.5 credit per qualifying rental instead of the standard .5 credit. When booking at southwest.com, enter MUAZ064 in the Promotional Code field to receive triple credit and U072722 in the Corporate/ID Rate field. This promotion is open to residents of the U.S. and Canada only for rentals within the United States.