Encrypted disk in Fedora 13

[feenberg-fCu/yNAGv6M at public.gmane.org (Daniel Feenberg)]

Is there a route through the GUI to encrypt an existing partion in Fedora 
13?

I have plowed through dozens of online documents showing how to arrange 
for a partition to be encryted at the time the OS is installed, but none 
mention how to add a partion on a new disk, or encrypt an existing (non 
OS) partition. A search through the menus doesn't turn up anything either.

Daniel Feenberg
NBER