In January 2011, the National Science Foundation (NSF) began requiring that researchers applying for grant funding must include in their proposals a data management plan. Similar to the National Institutes of Health (NIH)'s Public Access Policy, this requirement exists to ensure that the results of publicly funded research are available to taxpayers.
Universities and other research institutions are beginning to provide hosting services for their researchers' data sets. Researchers' needs for data storage vary widely by discipline both in terms of frequency of deposit and size of storage space needed. (Some research can produce more than a terabyte of data per day!)
Data storage and reuse isn't only of interest to scholars in the sciences. In the growing field of digital humanities, researchers perform text mining using the large corpus of digitized literature available through open access resources like Google Books and the Internet Archive.
Government and intergovernmental organizations have led the way in providing open access to data sets. A selection of these resources are listed below. As more research bodies begin to host data, this list will grow.