Going on a long flight overseas and would also just like an extra battery for other purposes. I checked out this site but don't know what to pick. Anyone have any suggestions? http://www.batterygeek.net/Batterygeek-net-MacBook-MacBook-Pro-MacBook-Air-Batteries-s/78.htm EDIT: I'm using a macbook pro 17 inch 2009. You can't change out the battery - I'm just looking for a good extra battery thats lightweight, and plugs into the power slot. Money isn't an issue.