Open Data Sources
In this workshop we a small dataset published by the OpenFlights project. This data is published under the Open Database License, one of several open data licenses that grants rights to anyone who wants to use or redistribute the data.
In recent years there has been a strong movement encouraging organisations to publish data openly on the web. As a result there are many public data repositories, both government and non-government, that you can source data from:
The Google Public Data Explorer indexes many public datasets and features an in-browser data explorer. You can also download the data to perform more in-depth analysis.
UK's Guardian Newspaper Data Store provides a wide range of data and data-based analysis. (Here's a giant list of just their data sets and the articles that mention them.)
The World Bank publishes its data catalog online.
Some countries are sponsoring open data "hackathons" to raise awareness and find new uses for their data, for instance GovHack in Australia.