(yes, it's been a while)
A very dear friend from college days turned me on to this tradition. The first person to say "Rabbit Rabbit Rabbit" to the other person, on the first day of the month, won. Won what? No idea. Won something. We'd sneak up on each other, we'd leave messages on the answering machine, or even ping if logged in to the UNIX system. No, there wasn't really email in those days .. not really.
Anyway, it's been a while - and I miss her.
Update: The Wikipedia rules all. Problem solved.