Built right into OS X Lion, Lion Recovery lets you repair disks or reinstall OS X Lion without the need for a physical disc.

The Lion Recovery Disk Assistant lets you create Lion Recovery on an external drive that has all of the same capabilities as the built-in Lion Recovery: reinstall Lion, repair the disk using Disk Utility, restore from a Time Machine backup, or browse the web with Safari.

Note: In order to create an external Lion Recovery using the Lion Recovery Assistant, the Mac must have an existing Recovery HD.

To create an external Lion Recovery, download the Lion Recovery Disk Assistant application. Insert an external drive, launch the Lion Recovery Disk Assistant, select the drive where you would like to install, and follow the on screen instructions.

When the Lion Recovery Disk Assistant completes, the new partition will not be visible in the Finder or Disk Utility. To access Lion Recovery, reboot the computer while holding the Option key. Select Recovery HD from the Startup Manager.

System Requirements
A Mac running OS X Lion with an existing Recovery HD
An external USB hard drive or thumb drive with at least 1GB of free space