Over the years, Robert Downey Jr. has played students, junkies, cops, sleazy producers, rogue U.S. Marshals and, um, Charlie Chaplin. And none of those roles seemed to be as much of a stretch as the one he's just signed on for: billionaire-industrialist-turned-mecha-hero Tony Stark, a.k.a. Iron Man.

According to The Hollywood Reporter, Downey will play Stark in the big-screen version of Marvel Comics' "Iron Man," to be directed by Jon Favreau (see "Have Doubts About The 'Iron Man' Movie? Jon Favreau Wants To Hear Them"). Shooting is scheduled to get underway this February in Los Angeles, with a reported budget of more than $100 million.

In the film, Stark — who, in addition to being a billionaire is also a master inventor (aren't they all) — is kidnapped and forced to build a devastating weapon. Instead, he develops a high-tech suit of armor, which helps him escape his captors and uncover a nefarious plot with global implications.

Stark first donned the Iron Man armor way back in 1963, making his first appearance in Marvel's "Tales of Suspense" anthology series. In his original incarnation, Stark was an M.I.T. graduate who traveled to Vietnam to help the American war effort with his inventions. Ultimately, he's wounded by a piece of shrapnel and taken into custody by the Viet Cong, where he's put to work developing weapons for the enemy. But with the help of a fellow prisoner, he develops a powerful metal exoskeleton in secret, and uses it to escape.

The movie version of "Iron Man" — which has been in various stages of development for years — will take place in the current geo-political climate, according to the Reporter. It's tentatively scheduled to blast into theaters May 2, 2008.

Check out everything we've got on "Iron Man".

Visit Movies on MTV.com for Hollywood news, interviews, clips, red carpet photos and more.

Want trailers? Visit Movies on MTV Overdrive for the newest, scariest and funniest coming attractions anywhere.