Licence plates

I was just wondering, does anyone else out there pay attention to the licence plates of the cars around you? I don't know why I do so much, but I don't think a car can go by me without me glancing at it to see if there's anything interesting. For example, on today's drive to work there were mostly just boring standard Colorado licence plates, but there was one old greenie truck plate and one Idaho plate that was some non-standard style (wasn't red white and blue).

I don't know why I do it--maybe because of my years living in Montana, which must have the highest percentage of vanity plates in the nation, or maybe I'm just crazy.