Luckily I've done this as a proof of concept. The key is to use the terminal for it. Apple hides the recovery partition by default in Disk Utility which makes it hard to clone. Fire up your terminal and let's get started.
diskutil list and find the partition name for Recovery_HD, it should be something like
What we're going to do with this is create a disk image with dd and then we can use disk utility to restore it to the usb drive.
dd if=/dev/disk0sX of=/Users/USERNAMEHERE/Desktop This creates a disk image copy of the recovery partition in a disk image on your desktop. Note, X is the number that you found from
Let dd run and the once you get your prompt back, you can quit terminal.
Open up Disk Utility and find the USB drive you want to clone to. Make sure that you have everything off the drive.
Click on the 'Restore' Tab. Drag your newly created disk image into the Source box, and do the same with your drive into the destination box.
click restore and let it run.
Once it's finished you should be able to boot from this drive, in theory.
I would like to note that I had an issue using this drive on a computer that had SL installed, which I find to be a bit odd but YMMV