This site tells you fun and random things that the post office will let you mail. So fun to do with kids for their cousins far away :) or ways to be the BEST pen pal ever.--Fun for the niece and nephew!
Camera Mail Document the voyage of postal mail! Over at Toad Haven, they sent out a package, "asking every postal worker who touched it to take a picture of the mail's journey across country." The package was sent from California to Interesting idea