The people who knew me on these forums back in 2001 would remember. Typical story: There was a wood. Council wants to build posh, expensive homes on it. My family think this is bad idea because they aren't affordable or necessary, plus would destroy a unique habitat since everywhere else near us which was like this bit of woodland has already been built on. We set up protest. Real protesters come to help us. We fight for 4 years. We lose. Woods get destroyed. Remaining protest community set up camp in untouched woods nearby while they look for somewhere else to go. They leave eventaully to help other protests. Yada yada.
But then this topic is about Portal Graffiti. :P Perhaps one of the reasons that the graffiti sticks in my mind is because it was such a nice touch in-game - Graffiti left behind by other test subjects who went insane. It was so simple, but it added a hell of a lot more depth to Portal's storyline. I really loved finding the cooking pans over the CPU Processors, too.
What a cool idea as a way of heating beans when you're trapped in an 'Android Hell'.