On Snow-Leopard, it seems that when I install a package, it requires to be "reinstalled" for every user. How do I do a system-wide install?
By default all packages installed by MacPorts are installed within the /opt/local tree. Make sure each user either has this reflected in their path, or calls the binary with the full path.
Failing that, check to make sure the prefix variable is set correct in the macports.conf file. The global file can be found at: