Airfare buster Southwest Airlines has put its Rapid Rewards frequent flyer program into mach speed. This week Southwest teamed up with the Hilton HHonors frequent guest program to offer triple the standard Rapid Rewards credits for every stay at participating HHonors hotels. Rapid Rewards members normally receive a half credit per stay. During the promotional period they will receive triple Rapid Rewards credit or 1.5 credits per stay. Southwest Rapid Rewards members earn one free flight with 16 credits. What makes the promotion even better is that you also earn points under the HHonors program. HHonors is the only guest reward program that allows its members to simultaneously accumulate both Southwest Airlines Rapid Rewards credits and HHonors points with each business-rate stay, a benefit Hilton calls Double Dipping. The triple dipping promotion will run between now and March 31, 2000. For a complete list of participating hotels offering this bonus, visit www.hiltonhhonors.com, or call 800/552-0852, and request faxback document No. 124.