in 9th grade, a couple fools i knew drew a bunch of penis' all over the biology room.
Wow, what a coincedence. In sophomore year, some kids in my class also took some chalk and drew a big dick on the black table. Then the bell range, they left to the next class, and some of us stood around looking at her. She laughed and was like... "What?". Then when she found it she was like "Oh my god, you guys are so lame!". So she started rubbing it off... the desk... with a rag and yelled "OMG it's not coming off!".
Most hilarious shit ever. Immature, but I didn't do it, I just watched
And once when I visited Austin, I saw a tourist pamphlet that had something to do with skydiving in Austin... In the background of the picture of some dude skydiving, you could clearly see on the ground (from the air) where someone cut their crops to spell something along the likes of how OU is better than UT. I thought it was awesome.