As documented here:

http://everything2.com/index.pl?node_id=1467753

The von Neumann Corrector is a very simple algorithm which removes bias from pseudo-random bitstrings.

To fit with previous challenges, the input could simply be bitstrings printed as text, provided one-per line:

STDIN:
110001100010
01011100111010

STDOUT:
011
0011

Whaddya think?