Moving /var partition to USB stick

I am currently running DesktopBSD as a live-CD and need to have a large /var partition because it is currently too small. I have a USB stick which is BSD formatted, and would like to have the /var partition moved over to it. How can this be done? Could I for instance use a symlink?

First, shutdown any relevant deamons (syslog, mysql), then, copy everything, preferably with rsync -av, then do a mount command like:

mount /dev/usb0 /var

Be sure to restart your daemons afterwards.