Xeni Jardin at BoingBoing gets the scoop on when American Airlines launches its in-flight network using Aircell GoGo service: She writes that it might be as early as this week on JFK, LAX, SFO, and MIA flights (that last one is Miami; took me a moment). Virgin is probably still a few months away, although they told Jardin that they're more prepared, but they have more integration to do.

Jardin notes that Virgin is thinking about what gets cached on planes. I would note that the idea of onboard media and caching servers is a great one, because it means that passengers could ostensibly stream or purchase downloadable digital content; and that whenever an airplane lands, its servers could automatically suck in at 802.11n speeds from a gate-mounted access point all the latest data to cache, including video.

On the cost of fuel to carry the Wi-Fi gear--probably a total of 200 pounds of dead weight and drag, based on information that Aircell and others have been giving out--I may have been close tot the mark when I suggested it was $50 for a cross country flight a few days ago.

The excellent Scott McCartney, author of The Middle Seat column in The Wall Street Journal, ran down the numbers on 10-June, and he says LAX-JFK costs about $500 per passenger when all the costs are figured out. But that includes all fuel divided by average passenger count: that is, the weight of the plane, everything in it, and its drag are all contributors.

That means that an added couple of passengers due to the availability of Wi-Fi; their willingness or the overall willingness to pay slightly more for the flight (which would be even fuller if more people want on); and the airlines' cut of a dozen or sessions per flight could clearly outweigh the gas cost.