Applying deodorant/antiperspirant.I don't want to be that offensive person on the bus who has forgotten it on a hot day.
Is the iron off? Is there plenty of water out for my cat? (Her kidneys are going bad...)
Then check my teeth, make sure nothing in the corners of the eyes, check the backside of my clothing in a mirror to make sure there are no surprises.
Keys (yes, I too have locked myself out recently at night in the cold and spent 3 hours running around town, trying to track down spare key sets from friends)
Blackberry, wallet, hand cream, Aquaphor.