PARK CITY, Utah  - After cutting her teeth for a decade in films like "Seabiscuit," "Spider-Man," "The 40-Year-Old Virgin" and "W," Elizabeth Banks is currently killing it as Jack Donaghy's baby-mama-to-be, Avery Jessup, on 30 Rock.

Returning to her roots at Sundance this year in two comedies, "My Idiot Brother" and "The Details," the native New Englander reflects on her favorite co-stars of all time, studying Shakespeare and swapping emails with David O. Russell.

WHAT FILM BROUGHT YOU TO YOUR FIRST SUNDANCE?

Elizabeth Banks: "Wet Hot American Summer," with Paul Rudd, in 2001. One of my all-time favorites. We had a giant cast and slept three to a bed with people on the floor. I remember going around handing out flyers trying to get people to give us the audience award.

HOW WOULD YOU DESCRIBE THE FILMS YOU HAVE IN THIS YEAR'S FESTIVAL?

Banks: "The Details" is a black comedy about the slippery slope of infidelity. Tobey Maguire and I play a couple. Laura Linney is our next-door neighbor. She's incredible in it. We are all obsessing over raccoons in the yard, meanwhile everything is falling apart around us. The director, Jacob Estes, had a movie a few years ago at Sundance called "Mean Creek." He's a really interesting writer.

WERE THERE CERTAIN FILMS YOU WATCHED TO HELP YOU CHANNEL SUBURBAN MALAISE?

Banks: Not really, but we did spend weeks rehearsing. It's wild because the two films I have in Sundance this year are with two co-stars that I have worked the most with. I think "My Idiot Brother" is my fifth or sixth movie with Paul Rudd, and with Tobey, definitely our sixth movie. This is the first time Tobey has ever acted with me when I've had blonde hair!

DO YOU THINK IT HELPS OR HURTS THE ACTING PROCESS TO BE SO COMFORTABLE WITH A CO-STAR?

Banks: Oh, it helps. Tobey and I have never played a couple, so it was interesting to delve into that together. Paul and I are like two peas in pod. I would make every movie with him if I could. We have a great relationship in "My Idiot Brother." It's one of my favorite characters I have ever played.

IN THAT FILM, YOU PLAY ONE OF THREE SISTERS (ALONG WITH ZOOEY DESCHANEL AND EMILY MORTIMER) WHOSE BROTHER, PLAYED BY RUDD, GETS OUT OF JAIL AFTER A MARIJUANA ARREST, AND ESSENTIALLY DRIVES THEM ALL NUTS?

Banks: Yes! It's about a guy who goes to live with each of his three sisters and ruins their lives. It's sort of in the vein of What About Bob? This person is ruining your life, but he's also solving your problems. He's more of idiot savant than a straight up idiot.

YOU STUDIED ACTING AT THE AMERICAN CONSERVATORY THEATER IN SAN FRANCISCO. HAS THAT TRAINING STUCK WITH YOU?

Banks: Yes, absolutely. The tools you get in a program like ACT are all about classic storytelling. You study Shakespeare, Ibsen, Chekhov and Tennessee Williams. You get a much better understanding of how to tell a story. I'm very proud of the fact that I feel comfortable getting on a stage. That's something that young actors are embarrassingly bad at.