AN INSURANCE COMPANY (boo! hiss!) has come up with an alternative Tube map, showing the number of steps walked by the average person between Tube stations. Does London have such a thing as an average walker? People invariably hare about like storm troopers on crack (this is good) or shuffle along like stoned tortoises (this is bad). Never mind pedometers, what I want is a cattle prod. The purpose of the map is to encourage lazy people to exercise - the British Heart Foundation recommends we walk 10,000 steps per day, which will help protect against bad things like stroke, diabetes and cancer (the downside is you'll inhale lots of nasties from traffic, get harassed by chuggers, and might be run over one of the capital's many psychopathic bus drivers).