A new search technology called Kaltix is being pionered by Stanford's PageRank team--a research group created to advance the mathematical algorithm developed by Google.
Apparently the new technology uses a new "personalization" of search results.
For example: the keyword "jaguar" might place car sites at the top of search results for someone who had recently visited automobile Web sites, but might lead off with Web sites about the cat for someone whose surfing history showed an interest in animals.
For more information read the article over at Cnet -
http://news.com.com/2100-1024_3-5061873.html