Dropbox should really do this. (vimeo.com)

Ah so many opportunities for mischief.

I'd recommend the postal service. It works really great and have a long record of actually delivering the stuff you give them. The "blue" boxes in the movie are btw very common in Denmark, when you order something you can have them shipped to the boxes, so you can pick your package up 24/7.

No, dropbox should focus on dropbox.