I would have been so excited, and had a total geek moment. My girlfriend would probably think I had the hots for old Asian business men or something.... it's probably a good thing I wasn't there. Seriously though, I would have run by the window holding up my DS and gave them the thumbs up.
EDIT: Better yet, bring every piece of Nintendo software you own, stand outside the window, and proceed to give it thumbs up, or thumbs down. Kirby's Air Ride, thumbs down. Mario Kart Ds, thumbs up. Nintendogs, thumbs down. Virtual Boy, two thumbs down. Gamecube, thumbs in the middle. N64, thumbs down. SNES, two thumbs up. Ha, that would be great... or at least in my mind. Then I'd post the whole video on YouTube.