I also include a dc invertor in case I get caught on a long rode trip or need to recharge between locations.
I also purchased a mifi for mobile wireless. It's a great device that allows up to 5 computers to connect to the wireless broadband connection. Great when you have peers that don't have their own wireless broadband yet and there is not available hotspot. It does have a battery for a few hours of unplugged use, but don't forget your charger for it too.