One of the coolest scenes in Iron Man 2 is when Tony Stark's briefcase pops open and automatically wraps the Iron Man suit around him. Now you can at least pretend that you're about to don your own Iron Man suit, by carrying around this replica of the case.
Unfortunately if you do pop it open, instead of activating an Iron Man suit, all you'll see is some boring pens and papers and maybe your laptop. Still, up to that point it really does look the part.
Perhaps you can find enough room to fit a fake leather Iron Man suit, although it would look kind of lame pulling it on and zipping it up.
The Tony Stark Mark V briefcase replica is a limited edition of 1000, and will be available in December for $460.