OK, I admit it. I totally ripped this idea off from my friend Izzy's excellent webzine Shimpmeat.
It was she who had the idea of reviewing things that people don't normally review - like grocery stores, or gynecologists, or intersections. Her only rule: the rating had to be from 1 to 10. When she told me about it, I got really excited and immediately wrote a review of every single roommate I've ever had. That review is still up on the Shrimpmeat site, and it reads like a JJ mini-biography.
Anyhoo, when I finally started this sellout commuting gig, it was only a natural extention of that premise to start reviewing everyone who sat next to me on the train. And there you have it - seatmate reviews! Maybe someday I'll review you, too!