I think urban dictionary is one of my new favorite websites. It is a slang dictionary that is set up similar to wikipedia (so don't believe everything you read). Anyone can add and vote on definitions. It's definitely worth checking out and learning a new thing or two. Here are a few of my favorite examples:
Totes: (adverb or adj.) stands for totally.
Amy: Isn't that guy over there really cute?
Ushe: (n.) Slang for "usual", used to describe a person's daily routines.
Amy: What are you doing today?
Kristen: Work, then the gym, then home for dinner, you know, the ushe.
Deep six: (v.) six refers to a grave (six feet under) deep refers to the ocean. Means to throw away.
Amy: This Boston cream pie yogurt is expired.
Kristen: Deep six it.