WebCite®, which used to be a member of member of the International Internet Preservation Consortium, is an on-demand archiving system for webreferences (cited webpages and websites, or other kinds of Internet-accessible digital objects), which can be used by authors, editors, and publishers of scholarly papers and books, to ensure that cited webmaterial will remain available to readers in the future. If cited webreferences in journal articles, books etc. are not archived, future readers may encounter a "404 File Not Found" error when clicking on a cited URL.... More Info »
Webcite won't archive 404 pages, pages requiring a login, and it always obeys robots and no-cache tags.
It offers transparent URLs, or short URLs (32 characters).