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? Tweet us the stories you're talking about using #InstantIndex or email us at ABC.WorldNews@abc.com and they could appear on World News.

First Cellphone On April 4, 1973, Marty Cooper, a Motorola engineer, placed the first public call from a cellphone.

Image credit: Jamie McCarthy/Getty Images

Here's Jimmy… Ending weeks of speculation, NBC confirmed today that after 22 years, Jay Leno will step down as the host of "The Tonight Show With Jay Leno" next spring. Jimmy Fallon, now the star of "Late Night With Jimmy Fallon," will take over shortly thereafter.