City of Toronto mayor David Miller announced TO's plans for an open data catalouge at Mesh09 last week.    Miller, who is in charge of the 6th largest government body in Canada, made a strong case for the benefits of open government data.  His arguments (transcribed from video) deserve repeating: 

The media, of course, have also changed.  Stories used to break in morning the newspaper, or on the evening news.  Now they break on the web, and they even break over twitter.  The newspaper often fades from memory over the next few days as the paper goes into the recycling bin.  TV news lasts an hour.  But the internet is an archive... Which means that the impact of every story, post, or video is increased dramatically. 

From a government perspective, it’s very important that the information that’s there permanently be accurate, and that the facts as we know them get out there in that permanent way. 

One of the interesting things though, despite the changes in the media, we, the City of Toronto, don’t need to rely on the media as much to tell people what we’re doing.  The web has given us a new low-cost high reach option to go direct to the people.

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I am very pleased to announce today at Mesh09 the development of http://toronto.ca/open, which will be a catalogue of city generated data.  The data will be provided in standardized formats, will be machine readable, and will be updated regularly.  This will be launched in the fall of 2009 with an initial series of data sets, including static data like schedules, and some feeds updated in real time. 

The benefits to the city of Toronto are extremely significant.  Individuals will find new ways to apply this data, improve city services, and expand their reach.  By sharing our information, the public can help us to improve services and create a more liveable city.  And as an open government, sharing data increases our transparency and accountability.

You can view video of the full speech here.