external drive

On a recent trip to Europe I underestimated the amount of drive space I would need to take with me.  I was forced to go to the nearest computer store and purchase another drive.  If I was going to have to do this I wanted to make sure that I picked up something that would at least be useful in the long term.  I use a Macbook Air when I travel and I hadn’t yet purchased any Thunderbolt drives to go with it.  At the time of writing (June 2012) Thunderbolt drives are still few and far between and those