What could be bigger or kept more under-wraps than a Star Wars flick? Well, Natalie Portman found out after being signed to star as Jane Foster in the film adaptation of the Marvel comic book Thor.

The production has been shrouded in so much mystery that Portman isn’t even sure who is calling her when the phone rings.

It wasn’t near this protected on the set of Star Wars, but Portman is quick to point out that technology has undermined the secrecy more than one movie production in recent years.

However, if you still want the scoop on Thor it might be best to go to the source. Marvel comic legend Stan Lee has tweeted on his Twitter page that he has agreed to make a cameo appearance in the film.

Click onto the two media bars for the extraordinary ways that motion picture and comic book companies protect their properties from Natalie Portman.

Thor is set to begin filming in January of 2010.