This weekend, Southwest Airlines returns to San Francisco airport, flying 18 daily departures. In 2001, Southwest shut down operations at that airport. But the airline has apparently decided to return to SFO to challenge United Airlines. Introductory fares of round-trip to Las Vegas for $118 and round-trip to Chicago for $189 can be bought now for travel between August 26 and October 31. See Southwest.com.

Photo: Yolopey, using a tilt-shift effect on the photo, via Flickr & Creative Commons

Fun facts: Southwest's website is a hit. It's the number one airline website for online revenue, according to PhoCus Wright. It's also the largest airline website for unique visitors, according to Neilsen/NetRatings.

Related: Southwest says the early response has been favorable to its test of a new boarding procedure. In a test that began this week in San Antonio, passengers are asked to board the plane one-by-one in an assigned order, rather than board in one of three groups. When passengers check-in for their flight, they're assigned individual boarding numbers. Once they board the plane, they still have their choice of seats on a first-come, first-served basis. According to Gadling, "They've doubled the size of the 'A' group and done away with the C group completely, and families with small kids get boarded between 'A' and 'B' groups."

Elsewhere: Spirit Airways CEO: "We owe him nothing"