At Chinese New Year the character 福 is very popular. It is pasted on doors and gates to bring good luck and fortune. Oftentimes the character 福 is pasted upside down, like in the picture above. This is called a 'phonetic symbol': different Chinese characters have the same pronunciation but different meanings.
福倒 'fu' 'dao' literally means 'fortune' and 'upside down'.
倒 (upside down) and 到 (to arrive) are both pronounced as dao.
So when the character 福 is pasted upside down it means that 'fortune will arrive'.