It shouldn't take as long for Matt Damon to lose his memory again as it did for Harrison Ford to pick the bullwhip back up.

Frank Marshall, who produces both blockbuster franchises, confirms a fourth thriller about amnesiac spy Jason Bourne is in the works with Damon and director Paul Greengrass expected to return for more lightning-paced mayhem.

"We're hoping it takes a few years less than Indiana Jones did," Marshall tells Sun Media during a phone interview. "We're busily trying to put it together, but it all depends on the script."

That could prove especially challenging because: a) they are out of Ludlum books to (very loosely) adapt and b) Tony Gilroy, the scribe who penned Identity, Supremacy and Ultimatum has become a white-hot commodity since helming George Clooney's Michael Clayton.

"Tony's off doing his own thing," Marshall notes, referring to Gilroy's next directorial project, the thriller Duplicity, which is currently shooting with Julia Roberts and Clive Owen.

One film buff Marshall knows is looking forward to more Bourne? His longtime friend and Indiana Jones director Steven Spielberg.

"Steven loves the Bourne movies."

LOOK MA, NO WIRES: Despite being 65 years old, Harrison Ford performed more of his stunts on Kingdom of the Crystal Skull than he did on any of the other three Indiana Jones films, reveals Marshall.

For that, credit technology that didn't exist in the 1980s. "Harrison was able to do a lot more of his own stunts this time because he could be on wires that we could erase digitally later," the producer explains. "Before we'd have to hide the fact it was a stunt double."

LIV LIVE: She's recently separated from one '90s alt-rocker -- her husband Royston Langston, ex of the band Spacehog and father of her son Milo. But Liv Tyler was in the studio with another last weekend, Evan Dando, ex of The Lemonheads. It was her recording debut.

"My friend Evan asked me to sing a Leonard Cohen song, which we recorded, Hey That's No Way To Say Goodbye. It's a beautiful song," says Tyler, soon to be seen in both The Incredible Hulk and the low-budget horror flick The Strangers.

"I don't know what's going to happen with it, but it's for his next album.

"I have a very musical family and I enjoy music a lot," says Tyler, whose father is Aerosmith's Steve Tyler and whose stepdad is Todd Rundgren.

"I'm an actress, so what I'd really like to do is, like, do a musical. I like the idea of old Hollywood, singing and dancing and doing something theatrical and fabulous."

THE NEED FOR SPEEDMAN: Also in The Strangers: Scott Speedman, whom we spoke with a few hours before his plane left New York to take him to Cannes for his bows in Atom Egoyan's Adoration.

"I've never been to Cannes, so I stayed in these last two weeks just to rest and get ready. I'm gonna have me some fun," said a pumped Speedman. "I just want to soak it in and have a blast."

Speedman had to campaign heavily with Egoyan to get the role of the uncle of an orphaned kid who imagines he's the offspring of historical figures.

"Atom liked me in My Life Without Me (with Sarah Polley), but he thought I was too young. I think the role was written for Bruce Greenwood or somebody.

"But we did an impromptu audition, I flew up and convinced him. That's my goal, to work with great filmmakers. He's an artist, but he's not a blacksuit-wearing pretentious prick. I'd do one line in his next movie if he'd let me."