Yep, I got it wrong too, should have wrote 11 hours and 5 minutes.

After initially suggesting that you might just like to mooch around Marunouchi, Ginza and Yurakucho and the surrounding areas this thread ended up arousing a sense of deja vu:
http://www.flyertalk.com/forum/japan...ride-free.html

Turns out that since then you can actually buy an alarm clock with the Yamanote Line jingles - I think they have at least two models now. About 7,000yen each.
http://www.mediatinker.com/yamanote2...es/009812.html