Once you have the installer application, you could (were you so inclined) dig into it (control-click, then Show Package Contents) and find the meaty center, a 3.74GB disk image (InstallESD.dmg, stored in the Contents/SharedSupport folder). You could then use that disk image to, say, burn a Lion installation DVD or create an emergency external boot disk.
Note: Installer Disk Image Anleitung