Southwest Airlines is paring 40 routes, including flights from Oakland, Calif., 8 flights from Chicago, and 7 from Baltimore. On the bright side, the airline is also adding 40 round-trip flights in markets it expects will grow this summer. In an attack on Frontier Airlines, Southwest is expanding in Denver, which will get new nonstop service to Los Angeles (LAX airport), San Jose, St. Louis, Philadelphia, Raleigh/Durham, and San Antonio. Another lucky city is Manchester, N.H., which will gain nonstop service to Fort Lauderdale. Yet another lucky city is Jacksonville, Fla., which will get nonstop service to Las Vegas.

Most of the new routes open May 10, but there's a fare sale on now for the new routes, with fares are as low as $158 roundtrip. Details here.

Skybus Airlines is expanding to three more destinations...Niagara Falls, N.Y.; Wilmington, Del. (near Philly); and Gary, Ind., (about 30 miles from Chicago). Find tickets at Skybus.com. For tips on booking Skybus's lowest fares, read our earlier blog post.

[Skybus recently cut its service to Bellingham, Wash., and cut back on its service to Burbank, Calif.]

FUN FACT OF THE DAY ABOUT BUDGET AIRLINES: Could you fly around the globe using only discount airlines, assuming that you wanted to fly around the world?

Answer:

Almost, but not quite, according to the website Budget Long Haul. Starting from Hawaii, you could fly WestJet to Toronto; FlyGlobespan to Manchester, England; Air Berlin to Luxor; Air Arabia to Mumbai; Jet Airways to Singapore; Tiger Airways to Darwin, Australia; and Virgin Blue to the Cook Island. But there are no discount airlines to fly you the last leg of the Pacific to Hawaii. Paging Richard Branson! (Hat tip to Vagablogging.net. )