Google is celebrating 25 years of the Tetris effect today. Of course, I hadn't got a clue what that was, so I looked it up. It's what I'll get one day from looking at LibDem blogs too much. Wikipedia summarises it thus:
The Tetris effect occurs when an activity to which people devote sufficient time and attention begins to overshadow their thoughts, mental images, and dreams. It is named after the video game Tetris. In the game a player rotates and moves different falling tetrominoes, or shapes made up of four adjacent square blocks. If the player can arrange the shapes so there are complete horizontal lines of blocks without any gaps, those lines are eliminated. The object of the game is to eliminate as many lines as possible before the shapes fill the screen.
On the subject of those celebatory Google logos, my offspring's school are doing a load of them in their Art lessons, to send in for a competition. Their given subject is "Our heroes".