Late Night dedicated the entire hour The Boss, which allowed for lots of interview time and multiple performances. The hit of the night, though, was this clip of Jimmy Fallon (as Neil Young) and Bruce singing Willow Smith's hit song.

Daniel Radcliffe appeared on Late Night to talk about Friday's debut of the latest Harry Potter installment. However, Jimmy wanted to make sure he knew all about his future Broadway costar. John Laroquette, and introduced him to Night Court.

Whether you've heard Biz Markie's original version "Just a Friend" or not (we're pretty sure you have) we promise you'll love this version. It begins as Jeff Goldblum's interpretation and eventually turns into a jam session with Biz and Jimmy.

Ev Williams and Biz Stone shared stories of Twitter's early inception — far back when it was referred to as "Jitter" and "Twitch." After, the group (including Rainn Wilson) read some tweets from #awwhellno, the Fallon-created hashtag that's trending worldwide.

It attaches to your XBox, and is just like Nintendo's Wii, but without any controllers. Microsoft Kinect reads your body's motions, which makes for fun games like volleyball and dancing! Also inside, Jimmy Fallon gets his Oprah on!

Today at Gawker.TV, Zach Galifianakis and Jimmy Fallon goof around with prosthetic arms, William Shatner covers Cee-Lo's "F*ck You," Joel McHale stops by Today, a coked up and/or rabid hamster attacks people, and a 60-second recap of yesterday's Colbert Report.

While filming a bit, Zach Galifianakis demanded that he (and the rest of the actors) use mannequin arms instead of their real arms. Filmed in a pool hall, logistics didn't work out quite as planned.

"This is the world's most pretentious rock star who starts out with lyrics that are so trite he sounds like he's making them up on the spot." Up on the Roots' stage the two share their love for fake singing.

On last night's episode of Late Night with Jimmy Fallon, guest Molly Shannon, Fallon and two audience members participated in a rousing game of Charades. With a nearly impossible title to pantomime, Fallon went straight for the chest. Literally.

Jimmy Fallon recalls the thrilling moment when he found out that Pee-Wee was booked as a guest for his show. Also catch his reaction when an audience member shouts "I love you!" Lastly they discuss his new understudy, Regis Philbin.

It's the role that Jimmy Fallon was born to play. And he nails it, a little too well. Boyish charms can get you far in show biz! Here the Biebs reflects on the housing bubble.

Well now! The title just about says it all, now doesn't it? Last night on Late Night, Jimmy and Johnny played a life-sized game of Operation. Watch what pretty much can be summed up as my childhood nightmare, inside.

The star and creator of Nick Swardson's Pretend Time appeared on Late Night on Friday to chat with Jimmy about his new Comedy Central show. What's to come on Pretend Time? Gay Robots, a Donkey Sex Bar, and Wheelchair Cat!

For a chance to win bird seed (an actual prize), contestants on Late Night regurgitate worms into their partner's mouth. In the case of a tie, there is a bird calling contest. All for a chance to be on television!

You might recognize Josh Lucas from American Psycho or the guy Elle Woods ends up with in Sweet Home Alabama, but did you know he's also an entrepreneur? Not for anything you've ever heard of, though. It's a drink garnish.

Technical difficulties aside, it was fun to hear Jimmy Fallon talk about how his "History of Rap" performance with Justin Timberlake and The Roots came to be. This is worth watching for his soulja boy "Superman" dance skills alone!

The Breaking Bad star and this week's SNL host was brought out to the old Malcolm in the Middle theme, which the Roots seemed more than excited to play. Plus, Bryan and Jimmy Fallon break into Bill Cosby impressions spontaneously.

When Late Night airs later on this evening, Justin Timberlake, Jimmy Fallon, and The Roots will perform a pretty fantastic medley of famous rappers. Catch the song (which features impersonations from Snoop Dogg to Eminem) early behind the cut!

Part of the reason Law & Order: SVU is so hard for me to take is that I recognize Christopher Meloni as the refrigerator-humping Gene from Wet Hot American Summer. This goofy video highlights more ridiculous behavior from the actor.

SNL returned tonight for its 36th season, and Amy Poehler hosted the premiere. One of the episode's highlights was Poehler's monologue, during which a plethora of guest stars—including Justin Timberlake and TIna Fey—showed up for a dream sequence.