Apple has released a new utility called the Lion Recovery Disk Assistant, which was developed to create a block level clone of an existing Lion Recovery HD partition to an external USB/Firewire volume with at least 1GB of free space. Although this offers no additional features when compared to a Lion Recovery HD partition, it can be used in the event the boot drive fails.
If you use Apple’s Lion Recovery Disk Assistant to clone your Lion Recovery HD partition to an external device, it must be formatted first as HFS Extended with a GUID partition table. Also, if your Mac shipped with Lion pre-installed, this clone will only work with your Mac. If you upgraded from Snow Leopard to Lion, this clone will only work on other Macs upgraded form Snow Leopard to Lion.