A dittohead is a fan of The Rush Limbaugh Show.

Saying "dittos" (or even "mega-dittos") was started by a Rush Limbaugh caller in 1988 as a shorthand way for callers to say they love the program and for Rush to never quit doing the radio show.

The term has been used as a snipe by people who see it as an example of groupthink allegedly encouraged by Limbaugh.

On May 30th, 2006, a caller decided to one up the common "Mega-dittos" with "Giga-Dittos". The Rush Limbaugh Show