deep thought, unfortunately this phenomenon reaches much farther than the part of rural America in which you live; I have been disgusted by its stupidity for years now right here in Chicago. The image of Calvin peeing on a car logo is most commonly seen; however he can now be seen peeing on the logos of other types of products as well.
Examples I have seen are Calvin peeing on a Reebok, Nike or Adidas logo, a record-label logo and even the words "west side" or "south side" embroidered in some cheesy gangsta-looking font.
The pitifulness of this blatant void of creativity/free thinking is extremely disappointing, not to mention the fact that most of the jerks displaying such images don't even know who the original Calvin was. Could anything be more tacky?