USB Key Disk Boot

Hi

Has anyone already developed or had experience with getting FreeBSD to run off a USB key disk?

I am looking to run a minimal FreeBSD build on a USB key disk as a network monitoring system, but I am having great difficulty getting information on how to do so. FreeBSD is my preferred *nix OS, but if I am not able to get a USB boot solution in a reasonable time, I will have to move my project to a Linux based solution as there are already Linux USB boot systems out there. 

All assistance is appreciated. I think that even if I could get some info on the BSD bootup sequence/etc I might be able to build something workable.

Best regards

JT
jtfbsd_at_jt.net.au