Statistics

Make google work for you! Search for a topic you're interested, then limit it by file type to target data. For example, try .xls or .csv

Wolfram|Alpha's long-term goal is to make all systematic knowledge immediately computable and accessible to everyone. Data can only be downloaded if you pay for pro, but still worth toying with.

A blog for math teachers; search the site to find links to all sorts of data!

This spreadsheet tracks the items published in Data Is Plural, a weekly newsletter highlighting useful and curious datasets.