He was alluding to my Gmail chat status line: "A man, a canal, Panama."
This is a deeply geeky in-joke.
The program finger(1) dates from the early days of Unix. By typing finger dmr you could find out if Dennis Ritchie was logged in, and information like his login, home directory, and shell. finger email@example.com would even run the finger protocol over the internet and give you the same information from the remote machine.
If you had a $HOME/.plan file, it would print out the contents, so you could tell everyone what you were doing: a primitive Twitter. (Chat and instant messaging are, themselves, just gussied-up talk(1).)
If you didn't have a .plan file, it would announce "No Plan."
I was too lazy to keep mine updated (really, everyone was), but I wanted to have it say something, so my .plan file always read "A man, a canal, Panama."
Yep: "no plan."
Vergil asked whether the Linux finger had ".plan" files. You bet. Try it yourself:
$ finger $LOGNAME | tail -2At least on Berkeley systems, root's default plan was "Rootin' around in the file system," but that seems not to be true on either Linux or OS/X.
$ echo "Whatever" > ~/.plan
$ finger $LOGNAME | tail -2