Governments and authorities like maps. They're a useful way of clearly saying this is mine, that is yours. They're also useful for saying where you can and more importantly, where you can't go. This is all too evident in a surprising map of where Russian visitors to the US were permitted to visit during the 1950s.

In the mid 1950s America and Russia were in the middle of the game of oneupmanship, with added nuclear weapons, that was the Cold War. Despite the uneasy detente between the two countries, if you were one of an elite group of Soviet citizens you were actually able to visit the United States. But not all of it. Large swathes of the US were closed to prospective Soviet tourists.

There's a saying that travel broadens the mind. It's a cliche but cliches generally come about because they're true. This week my mind has been considerably broadened, visting the Tandale slum on the outskirts of Dar es Salaam and attending and judging the Sanitation Hackathon, but more about that in a later post.

The week started in Chicago, the Windy City, which lived up to its name, being cold, windy and with crystal clear skies. It's a classic example of the American style of high rise architecture and the view from one of the meeting rooms in Nokia's offices were spectacular.