The motherlode (http://www.geofftech.co.uk/tubechallenge/) of Tube Challenge sites. (Unless, of course, you know better.) All Zone 1 can be done in just under three hours, doing the whole 274/275-station jing-bang lot in a day is an achievement.

Very cool list, bluedevi. I have a vaguely similar list of 113 ambitions (http://www.livejournal.com/todo/?user=jiggery_pokery), which I haven't touched for a while. It's interesting to see how many things I once wanted to do that I have less and less interest in doing these days, which probably says more about my ambition than anything else. You may be interested to see the way your attitude towards your own tasks changes over time, and there's nothing wrong with that.

Tying these together, one of the ambitions is to try the Tube Challenge at some point.