How to backup Store Apps? I have been searching and I didn't find an optimal solution for my problem. I have some apps purchased from the Mac App Store (Pixelmator, GarageBand), and other ones installed (Xcode).

I want to know is there an efficient way to backup this apps, and reinstall them after I do a fresh install of my system.

P.S. I want to do this because Xcode's download size is too big, and my internet connection isn't the better around... Same with other apps.
The receipt data from the Mac App Store is stored inside the application bundles, so anything that backs up your Applications folder will do the trick. You don't need to worry about your proof-of-purchase being saved in some other location on your hard disk.

Time Machine is probably the simplest to set up, as it will back up your entire hard disk.