Remove Storage iOS Apps on Mac

Is it possible to remove the Mac copy (iTunes/Mobile Applications) of all synced iOS applications (they are already installed on my iOS device)? They are currently taking up about 6 GB of space on my hard drive. I'm talking about the .IPA files. Thanks!

Quit iTunes. Then you can go into your "~/Music/iTunes/Mobile\ Applications/" directory, and manually delete apps using the Terminal or Finder. Before the next Sync, in iTunes control-click to hit the "Reset Warnings" menu item for your device. During the next Sync, iTunes may ask if you want to (re)copy purchased files from the device. Just say no. iTunes will be confused, but the apps will remain on the device, and not on your HD.

It would be better to first make a backup copy of your Mobile Applications directory with Time Machine, or to another HD, before messing with iTunes internal data like this.

If you remove the .ipa files (hopefully not from the OS X Finder, but through iTunes), you'll reclaim the storage space, but iTunes won't be able to alert you if there's a new update for that iOS app (which may be important if you get your updates via iTunes on your desktop/laptop Macs).