How can I clone my Lion-pre-installed drive to a new smaller hard drive?
It didn't take long - there is now an official assistant to roll your own external recovery HD. You need a USB drive with 1Gb of space and a free download.
The Lion Recovery Disk Assistant and OS X Lion: About Lion Recovery Disk Assistant will walk you through making an external bootable Recovery HD.
As the cloning software I like won't handle the Recovery HD yet, I've gotten good results by installing Lion onto the smaller hard drive and letting it make the Recovery HD.
It's easy to migrate the apps and data in post install rather than do it all in one step.