Again, the thing I want most in a case is a small footprint. I was originally going to go with a sleeve like a mintcase or joli original but I was thinking that I should try to find something just large enough to fit the charger.
Me too. Problem is as I tried different cases, the laws of physics interfered with my desire.
I could stuff my charger inside the pocket of my Bohdi sleeve, but the resulting bulge would not only be unseemly, the risk of impact on the charger pushing onto my MBA and possibly denting it was too high. For a while I carried the charger in a separate little bag and used a Bodhi sleeve (for work) and a Knomo sleeve on weekends.
I then saw the Booq Viper and thought "how'd they fit a charger in there?". There is a thread I made asking people for their opinions, and they were all over the place. So I decided to bite the bullet and buy it just to try it.
The charger makes an inevitable bulge. The advantage of the Booq is that it is made of a molded material and it provides what I consider to be a more reasonable level of protection. Because of the design, there is enough room for the charger, an external USB hard drive, AND the SuperDrive plus all cables. They made the lid just thick enough to hold the charger. Because the lid on a 13" MBA is big, there is extra room for all that stuff.
I imagine there could be some sleeve with a small pocket bulging out to carry the charger. But that bulge would worry me, especially how it could impact the MBA if I dropped it or hit against the wall while walking. These are sleeves we are talking about, so the protection is limited, but the molded design and materials of the Booq Viper provide at least some protection against dents. And at the end of the day, if the case doesn't at least do that, to me it's worthless.
Good luck on your search!