To celebrate Mountain Lion I decided to install a SSD in my aging but functioning Macbook Pro. I removed the optical drive, because I hardly use it anyway and installed the drive as a second drive. After that I installed a fresh copy of Mountain Lion on the SSD. The “old” disk now holds my home directory. It just feels like a brand new laptop.
Next step: encryption, you never know if someone gets his hands on your laptop. Getting the encryption on the SSD (OS X installation disk) is easy, just do what you always do.
However the home disk is another story. Since OS X only asks for your password after logging in to the system and by that time you already need your home directory this is not something that can be done without any scripting.
Luckily those scripts are around. So after activating the encryption for your second drive fire up your browser and follow the instructions on https://github.com/jridgewell/unlock (do read the read me, it will save you a lot of time downloading and stuff). Works like a charm.