Ok, so this is pretty simple. If gravity was reversed this very second, how much trouble would you be in? Let's not make this too scientific with the pull of planets and all... i.e. Are you outside? (bye lol) I'd hit the ceiling pretty hard but that's it. Of course my PC and desk might not be working anymore once they "fell". Yes, it's about 2:30 am and this is what I think up this late at night.