A popular way to pass time for many Postcrossers is participating in Travelling Notebook, TN for short. A TN is a little book about any subject you can think of. The owner puts a call on the forum to find people who want to write something about the chosen subject. When there are enough responses, the booklet is send to the first person in line. After he/she has received the book and added his/her share, the TN goes to the next person. The idea is to get the TN, completely full from the first to the last page, back to its owner. Hence the name... You can also ask to send individual pages, sending around a little book costs a lot and there is a posibility that your TN goes lost in the mail. I have here an example of a TN in which I participated.
TN Show me your country