As I found when I installed the latest edition of Mac OSx onto my macbook the just downloaded install media self destructs after it has finished reading it’s message.
In order to prevent this from happening you have to take a copy of the installation DMG from the package contents prior to installation. Looks like I’ll be downloading another copy of Lion shortly.
In addition Lion seems to create a 650mb partition called Recovery HD but this doesn’t appear to include the installation media which requires another download from the Apple servers. Not very friendly for people who don’t have easy access to the internet like myself.
Given the Recovery partition doesn’t include the installation media I have to wonder why it needs to be as large as it is – surely on base Macbook Air this is significant for a partition that contains very little!