On x86-64 configure complains about unsupported platform.
Patches available in mailing list, proper integration deferred.
Link to thread in mailing list:
http://lists.zeromq.org/pipermail/zeromq-dev/2010-September/006510.html
Steve, is this issue still open?
Close it. FreeBSD builds fine, still unsupported as I cannot get the test suite working. Any new problems should be logged new.