Starting in 1996, Alexa Internet has been donating their crawl data to the Internet Archive. Flowing in every day, these data are added to the Wayback Machine after an embargo period.
The Wayback Machine - https://web.archive.org/web/20080403013927/http://www.searchengineoptimising.com:80/forum/seo-tools/34-free-online-search-engine-optimisation-tools.html?option=com_frontpage&Itemid=1
here is great tool Search Engine Ranking . It makes daily checks on your selected keywords, it also can check your site's ranking such as alexa, compete and other rankings.