A fabulous article from the Guardian... Imagine if you took the historic records of everyone who died in the first world war. Then you matched them to one area to see how it had been affected. Or if you wanted to see if one part of your city had an epidemic of bedbugs. Or if you wanted to find out where the most guns are.
This is the work of data journalist
Patrick Cain, quietly and methodically producing strikingly interesting maps of his home city of Toronto.See more about the City of Toronto and other open data initiatives in Canada -
Article HERE
See also,

Article - How Canada Became an Open data Powerhouse - examples from Toronto