An acronym that expands to it self. eg:

pine?

pine? Is Not Elm

GNU

GNU is Not Unix

EINE

EINE Is Not EMACS

ZWEI

ZWEI Was EINE Initially

LIAR

Liar Imitates Apply Recursively

Cygnus

Cygnus, Your GNU Support

Emacs

Emacs Makes All Computers Slow1?

[Zinf|http

//www.zinf.org]: Zinf Is Not Freeamp

For the ultimate in RecursiveAcronym's see The Hurd, a pair of mutually refering RecursiveAcronym's!

XINARA Is Not A Recursive Acronym. Perhaps it should be! (apparently it's a town on the Tinos Islands, off Greece)

PINARA also isn't a Recursive acronym, but that's already been suggested on kuro5hin. This was the only [a-z?inara I could find in a google search in this context.

1? or Editing with MACroS