a couple of days later, the fare went down, you were kicking yourself. now there are actually tools that will tell you what s likely to happen with air fares. if you start at the web site bing./travel, they have a price predictor tool that will tell you whether the price is likely to go up, down or stay steady. and you can go to the web site, tripadvisor.com and you can enter your e-mail address and they will alert you if the fare drops below a certain price point. and finally, so many carriers today are tweeting these flash sales. so if you are a fan of twitter, then follow the major carriers. gregg: okay. rule number 3, which i always follow, be loyal to one airline so that you can rack up frequent flyer points. that s not the deal now? that can still work, but we ve gotten even better deals. there are these things called opaque fares. they ve been around for a while, but not a lot of people use them. something like a priceline or a