Woo hold your horses... (huh?)
I know "what's up" and it's variants "sup" and "wussup"! (West Coast?)
I know dollars can be called bucks or green as well.
Also some funny expressions like "kick the bucket", "bite the dust", "kick back", "beat about the bush" and some others!
Never been to the States before, nor any other native English speaking country. My sources are the media!
Note: media is plural