I am actually considering to design and implement a realtime ladder program that is just not for badminton, but for any sport. It would be great for clubs to facilitate some sort of live ladder competition on the web for their members, and everything would be interconnected via email ,icq, msn, aim, yahoo pager etc... to notify of ladder matches. Does this sound interesting? Tell me if any clubs have implemented this? It would be great convenience for people to challenge each other and everyone can get a good look at the ladder from anywhere.
There is a site called Sportsladders where you can maintain ladders on the Internet, for just about any sport. It's not as real-time as your idea, but you might want to check it out.