With immigration as a hot-button issue in an election year, the internationalization of Hollywood - nine of the 20 acting or supporting Oscar nominations this year went to foreign-born movie stars - begs the question: Is it easier for an actor to get a U.S. work visa than, say, a dishwasher?
"It is and it isn't," said immigration lawyer Mark Ivener, who has handled work permit and residency applications for numerous entertainers, including Ledger.
While English skills and hailing from a favored nation can certainly help, it turns out that star power helps grease the skids with government officials, too.
"It is easier if you are well-known," said Ivener. "Then you don't have to go through the labor certification process where you have to demonstrate to the Department of Labor that you won't be taking away a job from an American."
But for a struggling actor who's been waiting tables in London or Mexico City and would rather sling hash in Hollywood, the process is just as hard as it is for anyone else, say Ivener and others.
There are other criteria: Immigration lawyers say whether you're a scientist or a wannabe entertainer, it's definitely a drawback to be from a country on a terrorist watch list, or one that's predominantly Muslim, for that matter.
"That's still considered - unfortunately," said Kathleen Walker, president of the American Immigration Lawyers Association. Just being born in a country like Iran, Sudan, Cuba or North Korea, she said, leaves any person open to extra scrutiny.
"Which I don't believe in," she added. "If I were born in Iran but have never been in Iran since my birth, I'm still subject to additional screening."
And it can't hurt to be from an English-speaking country like Australia, England or Canada - most roles still go to fluent English speakers, after all, the immigration lawyers say.
All the same, Hollywood seems to be making way for an ever widening variety of foreign-born entertainers, from Jackie Chan of Hong Kong and Salma Hayek of Mexico to relative newcomers (and current Oscar nominees) Marion Cotillard of France and Saoirse Ronan of Ireland.
And it's one thing to come to America to shoot and promote a movie. Turning that success into a full-time residence in Beverly Hills? That's a little more complicated.
"There are really only two major ways people can come here permanently. They have to be sponsored by family or by a job," said Marie Sebrechts, a spokeswoman for U.S. Citizenship and Immigration Services.
In the case of actors, musicians or athletes, they are usually sponsored by the studio, record label or sports team that employs them.
"I got my green card through Motown," said Canadian-born comedian Tommy Chong, adding that the record label sponsored him after signing his band the Vancouvers to its label in the 1960s and producing its hit record, "Does Your Mama Know About Me." After the label dropped the group, Chong went on to fame as part of Cheech and Chong and eventually became a U.S. citizen.
Ledger became a star in Australian TV and films before he came to the United States. When a studio wanted him for a U.S. film it enlisted Ivener's help in getting him a nonresident work visa.
Ivener also helped British actor Anthony Hopkins obtain a visa and eventually U.S. citizenship after the actor came to the United States following stardom in Great Britain.
The key to success in these and other cases, say immigration lawyers, is in gaining enough attention somewhere else to attract a major studio or record label in the U.S. as a sponsor.
"It's kind of a corny analogy. But you know how banks only lend money to rich people?" said immigration lawyer Bernie Wolfsdorf. "It's the same framework with immigration. The top people can get the visas, and the wannabes and the up-and-comings not so much."
Although U.S. Citizenship and Immigration Services sets aside separate categories for actors, athletes and other entertainers who want to work in the United States, to have the best chance of receiving a visa one must also demonstrate "extraordinary ability."
"I had to amass all my gold albums and have photographs taken of them and get records of all the recorded events I'd played at and the amount of tours I'd done and the amount of money I'd made," said Keith Emerson of the British rock group Emerson, Lake and Palmer.
Soon after arriving in the United States nearly 13 years ago, Emerson said, he began to bump into other British musicians around Los Angeles who had gone through the same experience.
"We've formed a band called the Aliens of Extraordinary Ability, just to get together and jam," he said.
Meanwhile, the pull of the United States on foreign entertainers is simple, says Chong: It's the big time.
"That's the dream, if you're from another country, to come to the States," he said. "It was my dream since childhood."