Hey Trevor,
Setting up AFP is very easy if your host system is Linux and you have admin rights. You simply install the netatalk package [1] and start the AppleTalk daemon. For instance, if you're running Fedora Core:
yum install netatalk service atalk start
Nice suggestion ... I've been using AFP just locally between in house cpu's .. besides from being a bit slow (-er than say SMB even -- anyone else notice that) it does the job.
One question, just because I don't know jack about the AFProtocol ... is it easy to, say, do that through an ssh tunnel? Or .. is it not necessary and already encrypted?
-steve