Selling Single Items

I just think it is funny that while the US super sizes things and sells in bulk, this morning I saw a kid at the store buy one pencil and one piece of gum.

Things I have seen sold as single items that make me laugh:

a piece of gum
a pencil
a pen
a cigarette
a sample size of shampoo or conditioner (like the little packets attached to advertisements you get in the mail)
a single pill (of any kind - like ibuprofen for example)

I'm sure there are many more but this is all I can think of for now.