When Jason Reitman started his screen adaptation of Walter Kirn's novel Up in the Air, the multilayered tale of an isolated man who fires people for a living, feature-length filmmaking was still a personal career goal yet to be fulfilled.

When Jason Reitman started his screen adaptation of Walter Kirn's novel Up in the Air, the multilayered tale of an isolated man who fires people for a living, feature-length filmmaking was still a personal career goal yet to be fulfilled.

Following the Toronto International Film Festival's screening of Up in the Air in September, Reitman shared with a room full of journalists and most of his principal cast how he began, and how real-world circumstances necessitated a change of approach.

"I thought the book was incredibly relevant - not because it's about a guy who fires people for a living, but because we're living in a time where we're actually more disconnected than we've ever been," he said. "We think we're connected because we [communicate electronically], but we don't actually look into each others' eyes and have conversations anymore."

His work on the project began before Thank You for Smoking's breakout debut at the 2005 Sundance film fest, and from Reitman's description, this film and his first feature were initially two of a kind.

"When I started writing, we were in an economic boom and I was writing it more as a satire," he explained. "Over the six years that it took me to write this, obviously the world changed. These humorous scenes about getting fired weren't so funny anymore.

"As I approached the idea of writing them as dramatic scenes, I couldn't do it," Reitman admitted. "For whatever reason, I couldn't nail the authenticity of that moment."

His solution, inspired by economically hard-hit shooting locations St. Louis and Detroit: "We put an ad in the paper saying we were making a documentary about job loss," he said. "We were looking for people who were willing to go on record about how it affected them. We got a heartbreaking amount of responses."

Reitman ultimately put 25 respondents in the film, providing not just a paycheck, but also a SAG card for each. At a university appearance in St. Louis, he met an unemployed, fiftysomething musician who submitted a song about job loss on cassette; it now plays over the end credits, generating royalties for the songwriter.

According to George Clooney, who plays layoff professional Ryan Bingham, "As we were working on the film it became clear that it was less a comedy and much more about real people and real things, and suddenly it felt more timely than ever. We were at the exact right moment to tell this important story."

Reitman hand-delivered the script to Clooney's home in Italy to secure him for the starring role, but several of his perfectly cast costars went through a more stressful hiring process.

Vera Farmiga described a history with Reitman of meetings for previous films that didn't result in a part. When he came calling about Bingham's sharp, savvy love interest, "I was in the 11th hour of my first pregnancy and I was bigger than George and Jason combined, so I didn't think it was going to happen," she said.

Reitman wrote the part of Natalie, an ambitious young woman who's taught the ins and outs of Bingham's job, expressly for actress Anna Kendrick. He didn't want her to know that when she auditioned, however.

"It's like when you meet a pretty girl and you want to remain calm and not show your cards, so I went the opposite way," the filmmaker said.

"You're a very good actor," Kendrick told him. "I thought you hated me."

When she read for the part of Bingham's soon-to-be-married sister, native New Zealander Melanie Lynskey was actually afraid to speak out of character.

"I guess Jason isn't a fan of casting foreigners as Americans," she said. "I can't use an American accent when I'm talking as myself - I feel like an a--hole - so I didn't say a word to him in the whole audition. I was just nodding."

Turning to Reitman, she said, "Sorry I tricked you."

Reitman replied, "I'm thrilled that you tricked me."