Photo by diannehope at Morguefile.com
The End of Term Presidential Harvest has existed since 2008. The Harvest is a cooperative project involving several Federal depository libraries who archive copies of government (and other) web sites just before transitions to a new presidential administration.
Once archived, the information can be browse or searched. The previous End of Term archives can be found here: http://eotarchive.cdlib.org/.
Web sites are vulnerable information resources since information can so easily be altered or removed over time. According to the web site, "This harvest is intended to document federal agencies' presence on the World Wide Web during the transition of Presidential administrations and to enhance the existing collections of the partner institutions."
While participating libraries are managing the project, anybody may submit the address to a web page which they would like to see archived. To nominate an address, go to this link. If you think you will be nominating many web sites, then you can also install a bookmarklet to your browser. Find the bookmarklets and instructions near the end of this page.