The Australian government has launched data.australia.gov.au as the new home of Australian government public information datasets. There are more than 165 sets arranged into 30 or so categories, covering such topics as culture, planning, environment and education. The invitation on the site is to "[mash]-up the data to create something new and exciting!". The datasets are in various formats — XML, XLS, ESRI Shapefiles, CSV, etc. — each accompanied by basic metadata.
The United States federal government offers an increasing number of federal datasets free via Data.gov.
Partly in response to the U.S. initiative, Google released Google Fusion Tables this summer, allowing you to upload datasets and visualize them in various ways. IBM's Many Eyes also allows you to make datasets visually appealing and understandable.
Canadian federal data is collected and organized into sets by Statistics Canada, which, I believe, generally charges for their use. While there is no Canadian "free data" program comparable to the Australian and U.S. programs, there is something called the Data Liberation Initiative, managed by Statistics Canada, which actually is concerned with providing post-secondary institutions with cheaper rates and is "a cost effective method for improving data resources" for them.