The way I was able to do it was to just build everything as universal, which creates binaries that are both 32 and 64 bit. This was on a clean install of Snow Leopard using macports 1.8.1. Before installing everything, just add the line: +universal to variants.conf in /opt/local/etc/macports Of course, everything takes twice as long to build, but from the research I did and the question I posed at the macports forum, this is the only way to get it done, at least right now.
