I live in Brazil and travel a lot, sometimes I can prepare and schedule with a long time, does anyone knows a way or web site that can schedule fligths and just wait the best air fare to buy it?
I find that Bing travel is perhaps the best one since it consolidates all the other airline sites (except Southwest Airlines) and makes sense of fares. There is even a fare estimator that can give you some confidence about future fares. Once you're in the site, click on "track fares" and you'll be set for any changes that may occur. One note is that you have to sign in with Windows Live (free and not that hard to accomplish) before tracking.
Good luck and let us know what you think of the site.