I mailed a can of soda that was only available in the town where my college was to a friend across the country. It arrived intact, only slightly dented.

In college, Unilever mailed a bar of soap (in the normal bar-of-soap box) to every student on campus. The whole post office reeked of scented soap. Dozens wound up in fountains around campus. I can't smell that soap without being grossed out.

Virgin mobile phones mailed one of those Love Heart candies to business as apart of a "we love our customers" campaign. Unfortunately they got crushed by the post - resulting in white powder filled envelopes being mailed to lots of US business in the middle of the anthrax scare.