What to wear:The Social Network's antihero may win the award for the comfiest Halloween costume out there. To capture the look head to toe, don a sweatshirt (if you have an old '90s Gap one, even better), sweatpants or jeans, and the clincher: Adidas flip-flops. If you want to go the extra mile, get business cards made that say "I'm CEO . . . b*tch" to pass out.
How to act: Calm and confident, like you have so much money you don't even know what to do with it. Feel free to regularly check Facebook throughout the night.