I’ve started to compile a list of the places hosting data sets. Please contribute any suggestions of other data sets that are available.

• Google Public Data Sets Directory
• Amazon Public Data Sets
• Data.Gov
• http://datamob.org/datasets
• InfoChimps
• http://www.grouplens.org/node/12
• http://www.ncdc.noaa.gov/oa/mpp/freedata.html#FREE
• http://www.datawrangling.com/some-datasets-available-on-the-web
• Semantifi
• NYC Data Mine
• Data Market
• Retail store locations (paid)
• Quora questions about data sets
• Programmable Web API directory