party favors with a purpose

My roommate came home from a baby shower the other night and, as she caught me up on the chocolate bar and drinking games, set down a party favor on the counter.

I can appreciate the cultural need to send guests home with some sort of gendered doo-dad--but honestly, does it need to be something that is headed straight to the landfill? What about a party favor with a purpose? Perhaps a reusable water bottle with ballet slippers on it? A rosy coin pouch? A pink pill holder? There is room for creativity and personality here.

Resources: limited. Landfill space: limited. Room in your friends closet: limited. So what's with all of the worthless junk? How about handing out something that can be used (and better yet, re-used).