How to recreate Lion Recovery HD partition? I have a Macbook Air Mid 2011 which came pre-installed with Lion.

After a trackpad hardware problem I wanted to be sure that none of my programs was responsible for the problem. I booted into the recovery partition and used the disk utility program to repartition the disk with a single partition (the recovery partition wasn't listed there so I assumed that it was not affected of the repartitioning much like the hidden EFI partition) and reinstalled Lion onto that partition.

Later I noticed that this has in fact removed the internal recovery partition (although it allows the "web recovery" to start).

Now I'm searching for a way to "restore" that internal recovery partition. Is there a manual way to re-enable that partition? Or any other way to allow me to use Filevault 2 (which requires the internal recovery partition)?
I installed a larger drive in my MBP and cloned my original disk to the new drive using SuperDuper!  This process doesn't create the restore partition. Reinstalling Lion onto the new drive created the necessary partition for me. 

I reinstalled this using the "USB Key" installer run from a partition on an  external drive. My User accounts, applications, etc. survived the reinstall but I did have to run the updaters for the OS and reinstall Java after the Lion reinstall.

Note that I did all of this before enabling Filevault on the new drive. Not sure that mattered, but it seemed prudent.