"FOOTNOTE" is organized around primary source historical documents, many (most?) from the U.S. National Archives.  The site is well-organized, and offers a number of standard, useful Web 2.0 features:

• View and enlarge documents to discover hidden clues.
• Print documents to read later or add to your scrapbooks.
• Save documents to your Footnote Gallery.
• Search or browse all indexes on Footnote
• Create your own member page about histories, showcase original source documents, collaborate, or use it as a digital notebook.
• Share any document you find.
• Add People, Places, Dates & Text within any document, which then become searchable.
• Upload any image from your computer that you want to share with others.

The service costs $99 / year; there is no information on the site about educational pricing.  I wrote and asked them about this, and will let you know if/when I hear back.   Visitors to NARA facilities get free access to the site, and supposedly the records will be available for free on NARA’s Web site (http://archives.gov) in five years.