Get a month of in-flight GoGo WiFi on sale for 43% off when you purchase a one-month pass before you take off. The 30-day pass is $20 instead of the normal $35 and begins as soon as you purchase it. After the first month, the rate is $35. It's not clear what the cancellation rules are so read the fine print to make sure you can cancel if you only want in-flight WiFi for one month.
You will find GoGo WiFi on select flights by Air Canada, AirTran, Alaska, American, Continental, Delta, United, US Airways, and Virgin America. Soon, Frontier will join the fray. I've used GoGo in-flight WiFi and found the connection to be quite fast. It cut out one or twice but came back very quickly and was not a big deal.
GoGo WiFi starts at $5-$13 per flight, depending on the length of the flight. If you were to purchase two WiFi passes of $13 each on a cross-country trip, it would make better financial sense to buy a 30-day pass for $20.
In-flight Wifi for 43% off