Apple late Monday put up a new tool to help Lion users make their own restore tools. Lion Recovery Disk Assistant lets users replicate the Lion Recovery tool from the system drive on a USB flash drive or external hard drive. The option gives users a way to re-download Lion, run Disk Utility, or revive a system from a Time Machine backup even if the regular backup partition is lost or users start with a fresh drive.
The external recovery drive doesn’t amount to a complete install of Lion and can’t be used to install Lion without having an iTunes ID associated with a Lion purchase. As on the usual system drive, the resulting restore partition is invisible outside of the recovery mode.
Creating a recovery disk requires existing Lion Recovery drive. The USB drive needs at least 1GB of free space but doesn’t have any requirements for speed