A friend sent me a link to http://www.postcrossing.com/. The idea is to send postcards to people around the world, and you get them sent to you! I joined that day and sent my first postcard the very next day!!
The process is free, except for the cost of the postcard and postage. You can send up to 5 cards initially, and once they are registered as received you can send more. For each one you send you get one sent to you.
My first one went to a delightful lady named Mary in California. She wrote a lot about herself in her profile and so I felt I wanted to send a letter along with the postcard.
It felt strange writing the old fashioned way, but I think it's nice to receive handwritten letters.
I have boxes of postcards from years ago when I used to actively collect them - all sorted by country and some by theme (art and food!). Now I'll have more to add - plus it's nice to be a kind of ambassador for your country/city!!