This is just a quick note on how to redownload OSX Lion. I had a hard time finding this, maybe it’s common knowledge for everyone else, but…
There are tons of articles out there on how to create a bootable disk, or USB stick, etc., but all of them require you to have the original installer downloaded from the Mac App Store, which dissappears after you install it. Don’t even bother looking, I at least haven’t been able to find it.
Open up the Mac App Store, Option-Click on the ‘Purchased’ tab and the button should allow you to click on ‘Install’ again. After it downloads, cancel the installation and it should still appear in the ‘Applications’ folder.