TOM HANKS bundled up and hit the Sundance Film Festival in Park City, Utah, Friday night to support the world premiere of son COLIN HANKS' new flick -- and ET was there!

"I've been used to this guy, he's been around for about 30 years," Tom said of Colin, who brought the project to him. "He's a great guy, he's a good actor and this is really his thing."

Produced by Tom's Playtone Pictures, 'The Great Buck Howard' stars Colin as a law school dropout who responds to an ad for a "Road Manager and Personal Assistant for Celebrity Performer," hoping to break into the entertainment biz. Instead, he finds himself on a cross-country tour working for Buck Howard (played by JOHN MALKOVICH), a has-been magician who is trying to jump-start his career. Can Colin, with the help of a fiery publicist (EMILY BLUNT of 'Charlie Wilson's War'), create the comeback of a lifetime?

STEVE ZAHN and GRIFFIN DUNNE also star in the comedy, written and directed by SEAN McGINLY.