Google has been awarded US patent 7756887. http://www.freepatentsonline.com/7756887.html

Abstract:
"A method and system of modulating search result relevancy use various types of user browsing activities. In particular, a client assistant residing in a client computer monitors movements of a user controlled pointer in a web browser, e.g., when the pointer moves into a predefined region and when it moves out of the predefined region. A server then determines a relevancy value between an informational item associated with the predefined region and a search query according to the pointer hover period. When preparing a new search result responsive to a search query, the server re-orders identified informational items in accordance with their respective relevancy values such that more relevant items appear before less relevant ones. The server also uses the relevancy values to determine and/or adjust the content of an one-box result associated with a search query."

Techeye.com discusses this. http://www.techeye.net/internet/google-nabs-patent-to-monitor-your-cursor-movements

The abstract deals with using the information for search results. Can I patent using mouse movements instead to build user profiles?