HE WALKED between two skyscrapers on a tightrope, without a harness.
HE MADE IT ACROSS THE FIRST WIRE

THEN HE DID IT ACROSS ANOTHER 100ft WIRE WITH A
BLINDFOLD ON

You can watch it here:
http://www.skyscraperlive.com/wired-in.htmlWebsite might not work on chrome.
He walked across niagra falls with a harness (because they wouldn't let him do it without one. he didn't end up needing it)

He also walked across a shorter section of the grand canyon. Without a harness.

Some hilights from his previous feat:
http://youtu.be/MX_jFK9Zf5k