Photo Credit: Andrew Nelles/AP

How the power of social media – and a little city vs. city rivalry – led Jimmy Fallon to take an icy swim in Lake Michigan.

It started out as a friendly question posed to new Tonight Show host Jimmy Fallon during an interview with a Chicago newspaper: “Would you ever have (Chicago Mayor) Rahm Emanuel as a guest on your show?” The always friendly Fallon said something to the effect of, “He can host if he wants to. I’m kind of scared of that guy.”

Now, Chicago has always been known for tough politicians. The nickname “Windy City” has nothing to do with weather – the term was actually coined to describe the back-handed, often shifty political climate. So Chicagoans – like their politicians – are tough, and they’re always quick to stand up for the city, especially when a comparison to New York arises.

The mayor’s response to Fallon was a simple tweet: “Thx for the invite @jimmyfallon. You should toughen up for the big leagues. Do the Chicago Polar Plunge with me and I’ll join @FallonTonight.” The Polar Plunge was taking place on March 2 to benefit the Special Olympics, and Fallon was invited.

Photo via Twitter @ChicagosMayor

And that’s when the Twitterverse took over. Hashtags like #JimmyPlungeWithUs and #SwimmyFallon came from Chicago celebrities, media and athletes. They taunted him. They challenged him. They flooded Fallon’s personal and Tonight Show Twitter feeds. Media began to ask if he would man up and jump into Lake Michigan. Giordano’s offered him free pizza after he finished.

As a man who has used to social media to connect with a demographic better than any Tonight Show host in history, Fallon understands the power of the medium. And just a few days after the banter began, it ended when Fallon delivered one last tweet:

“Okay @RahmEmanuel I’m in. Lake Michigan will have a New York fish this weekend. #SwimmyFallon.”

Chicago rejoiced at its moral victory, and the Special Olympics celebrated a once-in-a-lifetime opportunity for global TV exposure. I saw it as a tremendous example of the dynamic and powerful influence of social media. (Later that night, Oscars host Ellen DeGeneres caused a temporary shutdown of Twitter after taking and sharing the ultimate celebrity selfie.) So those of you who wonder if Twitter’s here to stay should probably learn the language of 140 characters.

As for Fallon? He plunged.

With the Oscar race heating up – and just around the corner – these classic screen studies by some of our favorite Hollywood actors and actresses, produced by the New York Times Magazine, are small in size but large in style and presence. Check out these great small screen shorts.