Ahh, a new PC, a new install of iTunes, and all the apps I downloaded for my iPhone are nowhere to be seen. iTunes doesn’t offer me a way to redownload all the apps I installed, and what’s more, when I try to sync my iPhone with the new copy of iTunes, I get the following message:
Are you sure you want to sync applications? All existing applications and their data on the iPhone will be replaced with applications from this iTunes library.
I’m not especially inclined to manually redownload all those apps, but nor am I keen on the idea of losing them all. Fortunately, I had not yet nuked the old PC and a quick search revealed that iTunes stores your downloaded apps under My Documents\My Music\iTunes\Mobile Applications. I simply copied all the .IPA files from my old PC over to the new one and then, in iTunes, clicked on File > Add Folder to Library…, selected the folder, and breathed a sigh of relief as the apps reappeared in the Applications library.
Of course, all this could be avoided if Apple provided a way to back up one’s Applications library. iTunes does provide a “Backup” feature that involves burning your library to CD/DVD, but that isn’t quite what I had in mind.