Oooooooh!
O : oranges (which, sadly, I can no longer eat - think mouth sores from the citric acid), olives (green or black), ontological (did I really write that?), optimist (yes, I really am), open minded (usually), oxygen (not the TV channel, the air we breathe), October (in the Midwest its the month when the leaves turn, in the desert it's the month when outdoor swimming ends)....obviously I am struggling to think of " O " things...sigh O H, so any ideas of " O 's" I might have added but couldn't think o f?