Google announced that they were sponsoring free WiFi access at 47 participating airports. In addition, they're providing it for Virgin flights. The free Internet access will last from now until January 15, so if your flight is delayed due to weather, at least you won't have to pay to email your family and let them know.
When you log on, you'll be asked for an optional charitable donation to Engineers Without Borders, the One Economy Corporation or the Climate Savers Computing Initiative.
Free WiFi is a popular gift this year. Yahoo! is giving away free access at New York's Times Square for an entire year. eBay is sponsoring WiFi on Delta flights.
Microsoft started offering airport Wifi in September in a promotion that will also last through the holiday season. I ran into Microsoft WiFi as I was leaving NYC out of LaGuardia. I was offered twenty minutes of free Internet access in exchange for performing a single Bing search.