At one former job the DB programmers adopted STNG as their theme. One guy annoyed me to no end so I punk'd him. I patched his COMMAND.COM to call my own batch file instead of AUTOEXEC.BAT. My file edited his WfW machine name, so that at each boot he came up as "WESLEY". He'd change it and back it'd go the next day.

My batch file would chain AUTOEXEC.BAT so changes made there would still work. Needless to say, he was perplexed.