Personally, I've had more trouble with macports than necessary. (Mostly because whenever I type 'port', I still get command not found.) It's much easier just to download the source, ./configure, make, and sudo make install.
$ mate ~/.profile
# add "/opt/local/bin:/opt/local/sbin:" to beginning of "export PATH"
save
Now force a reload (eg. open a new terminal) and done ...