MySidekick is a social search engine that tries to improve on the search results offered by the major players by learning from the search habits of its users.
Mysidekick monitors the search terms used and the sites that searchers find most useful when searching. These sites are automatically tagged and the tagged sites are highlighted for future searches.
If you click on a search result (the results are powered by Yahoo!) and then return to the search page after some time, MySidekick will take this to mean that this was a successful/useful result. Such results will then move up to the top of the page in the "People's Choice" section.
For instance, after searching for 'internet marketing news', clicking on the E-consultancy link and lingering a while, any future searches now show this blog in the people's choice section at the top of the page.
This raises the question of how easy it will be to manipulate search results, though this may become less of a problem if and when the search engine gains more users.
A couple of other recent search engines have also attempted to harness human feedback to improve on Google and Yahoo!.
Mahalo, from Jason Calacanis, has produced some excellent results for a number of queries but, as it relies on a team of editors to create the results, it will struggle to deliver a comprehensive list of results. It currently has around 4,000 search results.
Another recently launched search engine, iRazoo, gets searchers to recommend links and rewards them with points which they can use to buy prizes.