From the unconventional and awe-inspiring to the hilarious and heartwarming, here's a look at some of the most interesting photos, videos and stories that have our newsroom talking today. What's capturing your attention, filling your inbox and cluttering your Facebook/Twitter feed? Respond below with the stories you're talking about, or tweet them to us using #InstantIndex and they could appear on "World News."
Zac Vawter, a 31-year-old software engineer, is using his experimental bionic leg to climb all 103 flights of stairs to the top of one of the world's tallest skyscrapers. After losing his leg in a motorcycle accident, Vawter was fitted with a prosthetic leg that is controlled by his thoughts, a trailblazing prosthetic development. According to the New York Daily News, the mechanical leg whirs into action when Vawter thinks thoughts like "climb stairs." He hopes to make it to the top of Chicago's Willis Tower in an hour.