Uh, is that Bumblebee hiding in the corner?
I put functional in quotations because the boot-jets don't work, it won't stop a single bullet (or rock), and the arc reactor is just a bunch of LEDs. Oh, and the briefcase looks like a homemade bomb. Besides that though, totally legit. The suit consists of 384 individual pieces of armor, over 4,000 LEGO Technix pieces and took more than 1,200 man-hours (that's like 2,000+ woman-hours) to design and construct. 1,200 hours -- good lord, that's 50 days. I haven't spent 50 days making anything! Unless 'my friends and family disappointed' counts, in which case I've been at that shit for years.
Hit the jump for a video of the briefcase to Iron Man suit transformation in action (complete with dryer-vent pipe arms!)
Iron Man Mark V Briefcase Armour [cosplay] (with a ton more pics and info about the build)
Fully Functioning DIY Iron Man Mark V Transforming Briefcase Suit [obviouswinner]
Thanks to Mark, who always handcuffs his briefcase to himself so people think he's carrying around some important shit. Smart thinking -- if you want your arm chopped off!