On Unix systems that support finger, the ".plan" file in a user's home directory is displayed when the user is fingered. This feature was originally intended to be used to keep potential fingerers apprised of one's location and near-future plans, but has been turned almost universally to humorous and self-expressive purposes (like a sig block). See also Hacking X for Y.
A later innovation in plan files was the introduction of "scrolling plan files" which are one-dimensional animations made using only the printable ASCII character set, carriage return and line feed, avoiding terminal specific escape sequences, since the finger command will (for security reasons; see letterbomb) not pass the escape character.
Scrolling .plan files have become art forms in miniature, and some sites have started competitions to find who can create the longest running, funniest, and most original animations. A compiler (ASP) is available on Usenet for producing them. Typical animation components include:
Centipede: mmmmme Lorry/Truck: oo-oP Andalusian Video Snail: _@/
See also twirling baton.