If you flip it over about half way through,
the bit left will be a paralleloburger.
(moomin-papa ; folkin class., Thu 4 May 2006, 2:04, archived)

Brilliant!
So simple, yet so perfect in it's solution.
( Enigmatic ™                 Voice No More                  ©, Thu 4 May 2006, 2:06, archived)