I'm starting to believe that I have an obsessive personality - probably not in a clinically definable way (at least I hope not), but there really are things that grab hold of me and take up my time...
My latest obsession is PostCrossing. The principle is simple: you sign up, you get sent the name and address of a random stranger somewhere in the world and you send them a postcard. As soon as your card has been received (and the ID code you must put on it entered on the site), your name and address get sent to someone and then you receive a card from a random stranger in turn. It sounds kind of pointless, I know, but seriously - I have already had such fun choosing pretty cards, writing a little message on them and sending them to "exotic" destinations (so far: 3 to the USA, 2 to Finland, 2 to Russian, 1 to the Netherlands and 1 to Australia), not to mention the excitement rush I get every time a new card arrives in my letter box: so far, I've received 6: 2 from Finland, 1 each from India, Germany, the USA and Russia).
I can't really explain why I enjoy it so much - but I do at least know I'm not alone in this (there are thousands of members according to the site). And I've already decided I'm going to have to pace myself - it could become a pretty expensive habit if I don't control myself. I'm going to try and limit myself to no more than 10 cards a month (which is already 10-15 € in total).
I'm guessing that I enjoy it for the same reason I enjoy Twitter and Facebook - it's all about connecting with people, getting out of the rut I'm in here at home. OK, so these people aren't friends (PostCrossing in particular, but Twitter too - even if there is more sustained contact), but it's contact, it's a little glimpse into the lives of others, and I love it.
Of course, I've always loved postcards (I have hundreds of them - every time I visit a country, a city, a museum, etc. I buy postcards), so I guess this PostCrossing thing was more or less made for me. But if you like getting mail, if you enjoy choosing pretty cards, if you get a thrill from "meeting" new people, it's a great hobby. Though probably not a great thing to put on your CV - it might come over as being a bit "lame" I guess!