I do, but there are situations that this won't help. I book week long trips where fly in, rent a car and make sales calls across a loop of multiple cities over hundreds of miles. My scheduling is conservative to allow for traffic and and other expected delays, so this often gets me to the airport rather early for my return flight. I use every hour possible to get work done on the computer, and often use up battery power to the point that I have little to none left for doing work on the flight. It angers me when I can't work on the flight home because I burned out the battery working in the terminal.