Getting things in the mail is turning into a treat for younger generations. I can think of a few:

- Automated postcards generated from your Facebook timeline or Flickr feed when you're traveling

- Simple/inexpensive invitations for parties, reunions, save the dates, etc. Hook it up to Facebook, too.

- Information distribution to parents of school children (how to register for online report cards, absentee reports, etc).

- Targeted political messaging (although there are already companies that do this)