The site gives you info about economic activity, ethnic origins, health, people out of work, whether there's loads of students, and whether people have got a bath, a toilet or a shower. You can't view pictures of people in their baths or showers, just in case you're wondering.
The site also gives you info about crime and types of crime, and how much your house is worth, if you're lucky enough to own one.
Neigbourhood statistics are more detailed but won't tell you whether your next door neighbour is having an affair with your spouse, unfortunately.
On that subject the net curtains are drawn.
You can find the site here. µ