Hi there, I just want to share my experience. Maybe it will prove helpful to somebody. Over the time I've had my MBA, I noticed the internal 64GB (well, just under 60GB...) were filling slowly but steadily despite the fact that I tend to have only the most necessary stuff on it. So I recently bought a small-size Hama microSDHC card reader and a Patriot 32GB Class 10 SDHC card in order to move my iTunes library and my Dropbox folder onto it and leave it plugged in permanently. I went the reader + microSDHC card route because I couldn't find a small-size 32GB USB thumb drive for less money than the combination I got. What I noticed quickly and tolerated for the last few weeks was: The MBA wouldn't hibernate anymore. Reduced battery life (by ~2 hours!); displayed even after a full charge without the MBA having slept in the meantime. => The thumb drive sucks a lot of power. After using the MBA off the battery until it shut down, the thumb drive was always reported as "not removed properly". I realized that I hardly ever use iTunes on my MBA, so I left the library folder on the thumb drive, moved the Dropbox folder back to the internal SSD and ripped the thumb drive out of the USB port. Now I have to plug it in every time I want to listen to some music, but as I said, I hardly ever do that on my MBA. The battery life (for which I bought it) is back to normal.