Blogs
Blogs are online diaries. The advantage over a conventional pen-and-paper diary is that you can enable others to read it. You can let total strangers access your diary (keeping your identity secret, if you so wish), and see their comments. Such a service could be interesting to a badminton player or fan. Players on tour can maintain diaries online and receive comments from fans across the world. This service will be included soon. Keep an eye.