Pen + sprinkler = get out of school free!
I will not be as descriptive or dramatic in this story as I was in my last. Last year, someone in my class made a small elastic gun that shot pens and pencils. Someone, who shall remain nameless, was screwing around during LA class trying to get a pen stuck in the ceiling with it. Whats the one thing you hit if you aim at the cieling and miss? A sprinkler. Black, smelly fluid (I know, black? wtf?) sprayed out everywhere as everyone in class eight one was screaming. Within seconds, the school alarm system was activated, and the entire school (~1000 students) was evacuated. 1/4 of the school was flooded, as were 4 computers. (Nameless) did get caught and was suspended from school for ~1 week. We got the rest of the day off school. If you can hit a sprinkler with one of these weapons, and activate it, It's basically a good way to get out of school free. You must have tremendous aim though. Someone with knowledge in the field of sprinkler systems said that (nameless) was extremely lucky that he did not set off every sprinkler in the school, which probably would have gotten us out of school for a week. (and got him suspended for the rest of the year, if he were caught)
remember, aim between the red part and the metal part.