Search engine referrers
This will log all of the search engine queries used to find your site in all of the most popular search engines. It will save each query and list them by how many hits that query has brought you. It will also show you the last 20 queries used to find your site. You can search through the database for a specific search phrase, list searches from a specific search engine and more. You also have the option of redirecting certain search engine strings to a certain page, so if someone comes to your website after searching for something like "free scripts", you can have that person redirected to a page on your site that has free scripts on it. The entire script is extremely lightweight and you simply include a single file in your webpage and the script does the rest. Current search engines supported: Google, Yahoo, MSN, Altavista, Mamma, Hotbot, Alltheweb, AOL, Teoma, Lycos, Ask.