'Now' is short for the colloquial greeting 'Now Then' and is used instead of the more common 'hello' or 'hiya'. It is shouted in a distinctive, elongonated manner, often exaggerated when under the influence of alcohol. "NOOOOOOOOOOOOOOOOOWWWWWWWWWW"
C.dog: Hey can I go to your house on friday?
Dec the Shizz: Yeah!
Dec the Shizz: YES!
Dec the Shizz: NOW!
C.dog: yes cause now is Friday...
Dec the Shizz: you should put this on urban dictionary! the men and women need to know!!!