What Does it Mean To Be an “Owner” or “Mere Possessor” Under 17 USC 109?

In light of my last posts about first sale as applied to copies “rented” through Rhapsody, I’ve had an interesting exchange about what it means to be an “owner of a copy” in terms of 17 USC 109 (the “first sale” doctrine), and what rights you have to a lawfully made copy you rent from Blockbuster or Rhapsody. My thoughts are admittedly rough — does anyone else have a clearer answer?  Regardless, thanks to my interlocutor, “analoghole,” for some old-fashioned copyright geekery.