Units of Measure: Might quikmaps help visualise big units in the locality?

This week we have been thinking about the relationships between units of measures, presenting an image of a cm and a m is fine, but how do you present a picture of 1km to a group of 7 year olds? I was pondering this evening on how useful quikmaps might be for this, estimating and plotting out the distance in the locality. Driving into school this morning I used the odometer in my car to help me rough out a kilometre so I could share it with my class, and this evening have set up a blog to use as a modelling tumble. What do you think, this map features a prominent landmark and an imaginary walk which is approx 1km long?