Yes, at school or in browser games.
Ah well, i used to ask for stuff for next years units (i'm like that), so how about http://ninjakiwi.com/Games/Tower-Defense...b9vBfmrQ2A good time passer.
Next time take a USB with easy games, and remember, you can't have a school PC without Counter-Strike installed.
It's a complete waste of time, nothing better than it.