Just sitting on the gate (Airport Vienna) to my flight to Barcelona, TechEd. I didn't expect that I have wireless available here. And it is free (during a trial-period).
At the airport in Seattle wireless was available, too. However, in Seattle I didn't receive the IP address for a gateway. There it seems it is necessary to buy the wireless connection before use.
I didn't see a wireless network at the airport in Washington, DC.