$ sudo port version dlopen(/opt/local/share/macports/Tcl/macports1.0/MacPorts.dylib, 10): no suitable image found. Did find: /opt/local/share/macports/Tcl/macports1.0/MacPorts.dylib: no matching architecture in universal wrapper while executing "load /opt/local/share/macports/Tcl/macports1.0/MacPorts.dylib" ("package ifneeded macports 1.0" script) invoked from within "package require macports" (file "/opt/local/bin/port" line 39)
原因はLeopardからSnow Leopardにアップデートしたかららしい。
Snow Leopard用のMacPortsをダウンロードして、インストールしなおす。