A mother's son named Will has started the Postcards For Mom project. The project invites you to send his mom a postcard from wherever you are. Mom has no idea her son started this stunt, but she's happily receiving loads of random postcards from people she's never met.
Sounds a bit like Amelie to me. I hope mom is entertained when she gets my postcard.
Beside postcards, Will also has a featured item each month to send mom. Bottle caps for January and business cards next month.
A friend of mine started doing this to a friend of his (someone I hadn't met at the time when it was started) several years ago.
The difference was that every person sent a postcard that said the same thing, and didn't sign it. So he has all these postcards from all over the place, with the same message in different handwriting. Pretty funny.