Flights to and from more than 70 cities in the U.S. are discounted on Southwest Airlines, a fact that travel website Smartertravel.com alerted me to this morning. According to the Southwest site, sale prices require 10-day advance purchase and must be purchased by May 3, 11:59 Pacific Time. Sale prices are good on select travel from May 11 through Oct. 31, for travel on Tuesdays and Wednesdays, though sale fares may be available other days of the week on a limited basis. Destination from Minneapolis include Oakland and Los Angeles, Calif., Nashville, Tenn., and many more.