AHEM.  At least two people are spreading misinformation here.

A few points:

* There is, in fact, a port of AFS to NetBSD.  It's distributed by a
  group at MIT, and I personally help maintain it.

  It's true that it's not `support by TransArc,' but none of the ports
  to free OSes are.  If that's really a criterion, use Solaris/x86 or
  something.

* There is, in fact, a port of Arla to NetBSD.  AFAIK, it's one of
  their test platforms.

  However, Arla is not very reliable yet.

So, you can certainly use AFS under NetBSD.  (In fact, this mail
buffer is being autosaved into AFS from a machine running NetBSD
1.3H/sparc.)