∞ Here's what to do If you have Lion GM installed and want to download it from the Mac App Store

I little tip that was sent to me on Twitter this morning. For those os us that had Lion GM installed, you found that you couldn’t download the retail version of the operating system from the Mac App Store. Mine said a newer version was already installed.

All you need to do is hold down the Option key on your Mac and click the install button on the Mac App Store and it will download for you.