4. Software pirate
Real software pirates are mostly pretty boring-looking. And dressing up as a high-seas pirate is horribly overdone by now. But who says you can't do both?
This outfit should be a haphazard mashup of eye patches, Defcon badges, tricorner hats, worn-out T-shirts from ThinkGeek, and a treasure chest of trade-show swag. Instead of a pistol, carry an awesomely nerdy Super Soaker, and if you're of legal drinking age, make sure to mix your Captain Morgan with an energy drink worthy of late-night hackathons.
A parrot who can rant in l337-speak would be a fine addition, too.
Photo by James Martin/CNET News.com