I got a free messenger type bag from my bank today, because I put some money aside and filled in a form  ;-)
It's a nice shoulder bag (not that I don't already own oodles of bags, but hey, it's free and I'm Dutch) albeit rather blue.
It has a transparent part in front, where you can put something you'd like to be visible from the outside.
Of course, that makes it totally suitable as an instant BookCrossing bag. Pimp my bag!
The slogan reads 'Read and Let Read'.