Do you know the memory game? It's very popular with breakfast cereals manufacturers - most of them tend to put one on the back of each box. It is much more easy, although, to play the computer version of the game such as Easy Memory.
     Easy Memory is a well-known game for kids (or usually a party game for adults) where you have to open matching pairs of cards on a playfield. You can display two cards at a time. If they match, they stay displayed, if they not, they get hidden again. The goal is to open all the cards in the minimum possible amount of turns. The game trains one's memory as to minimize the number of turns you should remember all previously open cards.
     The game is actually a Java applet that gets displayed on a local page. The page offers external links to the developers' website and the online version of the game. Download it today and see that for yourself.