The first thing I saw was Gopher, and I don't remember what I searched for. One of the first websites I visited was called "graf-art" and had graffiti pics categorized by regions, and a separate category for trains. It never occurred to me that LA graffiti would be different than Chicago, or Poland graffiti. And since trains travel, they have many styles. Now I'm always checking out the artwork on trains. I call them "mobile art galleries".