The Ultimate Blunder
The Ultimate Blunder is Tim Krabbe's term for when someone resigns in a winning position. You can find his collection of examples here: http://timkr.home.xs4all.nl/chess2/resigntxt.htm.
I felt pretty clever for a little tonight while after playing Rd1 - h1 in an online blitz game, which caused my opponent to resign. See if you can find the much more clever way for him to completely turn the tables. Please leave answers in the comments.