You're not going to believe this when I tell you, but Southwest Airlines is preparing to celebrate 50 years of service. To celebrate this milestone, the low-cost airline will be offering travelers a chance at $50 one-way tickets. You have from now until February 8 to book your flight which needs to be done 21 days before you're set to travel. Fares are good for travel within the continental U.S. from February 9 through May 26. You can also get tickets for travel between the continental U.S. and Hawaii or to and from San Juan, Puerto Rico, and international travel. As with any deal, flights and seats are limited so you must act fast on the Southwest website.