If you work on a supermarket checkout, please try to slide the customer seperator bar to the back of the queue so that I don’t have to lean over other people’s shopping to pick it up.
If you design websites that require an address to be entered – please note that not every city is in a state/county so don’t make that field manadatory. London is such a city, and on far too many databases, my address will be listed as London, Not Applicable, UK.

Or as “London, London, UK” :)