Something to with the boost-filesystem package it seems ... maybe that it wasn't compiled for 64bit?
Hmm, boost 1.53 is installed with the "+universal" variant from MacPorts, and there's no separate boost-filesystem port, so that looks to be it. I do have a /opt/local/lib/libboost_filesystem-mt.a file in that location. I did try running the command with 'sudo' in front, wondering if it might be local filesystem permissions, but that doesn't help either. I'll try re-installing the boost port and see if that helps. Thanks!
No luck; still getting that error. Is anyone else's darwin/osx gcc-fu better than mine and can get a Mac binary compiled? I can muddle my way through C code (I'm a PHP/Python dev, mostly), but all the compiling nuances I haven't gotten my head around entirely.