Just recently I read a blog by a lady who had signed up for Postcrossing - I thought it sounded interesting so I had a look and signed up too.
Basically, you sign-up (for free) and get the addresses of other members around the world so you can send them a postcard. Each postcard has a unique ID which you write on it with your message and when the postcard arrives the recipient logs it online. Your address then gets given to another random member and you receive a postcard in return.
Already I have sent cards to Germany, USA, Russia and China and today I have just received my first card back (see the photo above).
I thought it would be a fun way of looking at Geography with the kids and there's something nice about getting post that isn't a bill isn't there!
If you'd like to find out more have a look at their website at www.postcrossing.com