After avoiding it for many years, it's finally come time to set up a
TFTP server.

My gut reaction to setting up TFTP is "security, security, security". 
The primary purpose of the server will be to store config files for
various devices (router and switches mostly).  TFTP sounds insecure
from the very conception.  Are there any guides to setting up a sane,
secure TFTP environment?

-Brian