Caffeine point value - all things approximate. 1 point = 35mg.
Green tea - 1 point
Diet cola - 1 point
Black tea - 2 points
Coffee - 4 points
Over the past week or so, I've reduced to one coffee and two black teas per day, so that's 8 points total or approximately 280mg per day. I had been counting a 12oz diet cola as equal to a black tea, but now I see they're not. So that's nice.
My previous consumption had been roughly 5 coffees and 2 diet colas per day for 24 points or approximately 840mg per day. So there you go.