It is rumored that a long line of 200 meters has recently been walked, as described in this forum here:
However, there is little official documentation validating this claim. There is, however video evidence of another long line walked on July 1st, 2008 by Stefan Junghannß in Dresden, Germany.
This line is claimed to be 171 meters, or 561 feet. (breaking Damian Cooksey’s previous record of 506 feet). Congratulations to Stefan!