I SPY NY: Michael Cera, Jenna Elfman and More

I spy in NY…

Michael Cera attending a screening for new flick Youth in Revolt at the Union Square Regal Cinemas Tuesday (top photo), a very pregnant Jenna Elfman leaving The Late Show with David Letterman Monday (middle photo), Sarah Jessica Parker getting her hair did at John Freida Monday (bottom photo), Josh Madden DJing at Eldridge Wednesday night, and Ashlee Simpson shopping with son Bronx Mowgli Wentz Monday.

John Mayer Gets Intimate at Live Letterman Set

“I’ve been up since three in the morning,” says John Mayer. He’s speaking to a handful of American Express cardmembers who purchased tickets to see Mayer perform an intimate, hour-long “Live at Letterman” set on CBS Thursday night, but Mayer wants us to know he’s not complaining.

“Being up this long allows you to have as much fun as possible,” he adds, then catapulting into “Perfectly Lonely,” a plucky blues ballad off his latest release, Battle Studies.

Mayer soaked the hour up with tons of Studies tunes – “Heartbreak Warfare,” “Friends, Lovers or Nothing,” Poison Ivy favorite “Half of My Heart,” and the controversial “Who Says,” which Mayer tried to clear up with a Boyz II Men comparison.

“Is ‘I’ll Make Love To You’ about making babies?” he asked the audience. “Not unless you’re trying to make babies.”

“It’s not [about making babies] if you’re listening to it while you wash your car,” he laughed.

Mayer didn’t venture too far back into his 10-year catalog – sticking to mainly Studies tunes and two songs off of 2006’s Continuum: “Gravity” and “Waiting on the World to Change.”

But we were ever impressed with his melodic finesse and comedic ability!

He even managed to throw a couple seconds of Jay-Z‘s “Empire State of Mind” into the bridge of “Who Says”!

Check out a glimpse we snuck of Mayer performing an extended version of “Friends, Lovers or Nothing,” above.

Quote of the Night

“If there’s one thing people know it’s that I’m in Roger Federer‘s head. Definitely. That’s probably as consistent as gravity.”

–Andy Roddick tells David Letterman

The Killers Fairytale Performance

In case you missed The Killers‘ fantastic performance of “A Dustland Fairytale” on the Late Show with David Letterman last night (the Las Vegas foursome brought out an entire orchestra), Poison Ivy has you covered!

Let us know what you think in the comments below.

Dolly Does Letterman

Dolly Parton got all dolled up for a performance of “Backwoods Barbie” on the Late Show with David Letterman Wednesday.

The jam, off her latest record, will also be featured in Parton’s new Broadway show, 9 to 5!

Check out the stellar performance above.

Beyonce Rocks Letterman

It’s a great day to be a New Yorker!!!!

Beyonce hit the Late Show with David Letterman Wednesday night to perform her latest hit “Halo,” for hundreds of fans.

Check it out above!!!

Seth Rogen Wants to Fit the Part

Now that he’s in every movie ever, Seth Rogen wants to fit the part!!

It’s a shame he can’t fit into his own tux though!

He’s lost so much weight, he’s practically swimming in those slacks!!

Rogen hit the Late Show with David Letterman Monday to promote his latest(s): Monsters vs. Aliens, Observe and Report and Funny People.

Don’t go crazy with the weight, Seth. We like the old you!

Christina Applegate Does Letterman

The always lovely Christina Applegate poses for a photo on the way out of Late Show with David Letterman Monday.

Hot or cold, rain or shine, the girl’s always smiling!

Even on New York’s coldest of nights!

Ben Stiller Parodies Joaquin Phoenix

Ben Stiller hilariously showed up to last night’s Academy Awards dressed as actor-turned-rapper Joaquin Phoenix.

Alongside a serious Natalie Portman, Stiller mocked Phoenix’s recent behavior during Late Night with David Letterman, nervously looking around the room and at times, even wandering off the podium!

The only thing that would have topped the act would be if Stiller decided to rap like Joaquin, too.

Jonas Bros Do Letterman

The Jonas Brothers visited the Late Show with David Letterman in New York last night, but not before braving the cold to sign autographs for waiting fans!

Thanks for being u, boys!!