Jon Favreau, the mastermind behind the Iron Man films is a regular user on Twitter and this week, he’s been creating a lot of buzz by posting images from a “geek tour” of his personal at-home collection of goodies (which of course included some cool Iron Man collectibles).

But that’s not all – Favs is using Twitter to keep his 20, 000+ users up to date with where they are in production of Iron Man 2. This week he’s been reporting on rehearsals of the main cast and he was kind enough to share a picture from last night’s rehearsal with us.

Sam Rockwell will be playing Justin Hammer, Tony Stark’s business rival who’s a multi-billionaire industrialist and later a criminal financier and villain.

Here are his messages from Tuesday regarding the rehearsals with some of the main characters:

“Rehearsed today with Gwyneth. She looks ripped. I gotta read GOOP and see what the hell she’s eating.”

“Great rehearsal today with Gwyneth, RDJ and Don Cheadle.”

Last night he reported that he rehearsed with Sam Rockwell and posted this pic:

I think Sam Rockwell and Robert Downey Jr. will have great chemistry on screen but I’m curious as to how much of the movie will be focused on his character with Mickey Rourke’s character most likely acting as the featured villain.

What do you think of Sam Rockwell playing one of the villains in Iron Man 2?

Iron Man 2 opens in theaters May 7, 2010

Source: Jon Favreau