5-O goes back even further than California late 80's. It's origins are a reference to an old 70's TV show called Hawaii 5-0 starring Jack Lord. The police were 5-O and eventually the show lingo caught on as hip among petty criminals in southern California.
A game originating with baby sitters in the north east in which fruit loops or similar O shaped cereal is poured into a toilet and young boys are instructed to aim for certain colors. An alternate method of toilet training.
"Aim for the red one Derek! Good job! You won Piss-o's today! Wait untill I tell your mom when she gets back from Italy."
a container full of roofing nails, generously distributed on some bastards driveway who has wronged you somehow in the art od road etiquette.
"that fucker cut me off so I follwed him and found where he lives. This morning, I filled my empty coffee cup with a handfull of 1 1/4" roofin nails and flung it in his drive.Hope he enjoys a hot, cup o nails!
6 o'clockhot is where the temperature is so high, you can't do anything until 6:00pm in the evening - you just want to lay low and as close to air conditioning as possible!
Cedric The Entertainer often uses this expression to describe the Southern states of the USA.