Google responded to some of these concerns by applying the following change in privacy policy:
"Today we're pleased to report a change in our privacy policy: Unless we're legally required to retain log data for longer, we will anonymize our server logs after a limited period of time. When we implement this policy change in the coming months, we will continue to keep server log data (so that we can improve Google's services and protect them from security and other abuses)—but will make this data much more anonymous, so that it can no longer be identified with individual users, after 18-24 months." (14 March 2007) http://googleblog.blogspot.com/2007/03/taking-steps-to-further-improve-our.html

However, in May 2007, the Financial Times reported that:
"Standard search information is kept about everyone who uses the [Google] search engine, and privacy groups are concerned that even this ostensibly non-personal data can be used to identify individuals and create profiles of their political opinions, religious beliefs and sexual preferences."
 http://www.ft.com/cms/s/2/dc89ec96-0a24-11dc-93ae-000b5df10621.html

Now Ask.com, who have a much smaller share of the search engine market, have responded by making their search engine have a very visible option that sets no cookies and therefore no collection of the search data entered by surfers.
http://sp.uk.ask.com/en/docs/about/askeraser.shtml

Perhaps this will prove to be a winner which will give Ask.com's engine a little boost.

To make Ask (or any other provider) your default search engine in Internet Explorer 7, click on the Search Options button to the right of the search magnifying glass icon, find more providers, choose the one you want and in the pop up dialog box tick "make this my default search provider". Once you launched a search, you can easily turn on AskEraser by clicking on the link on the top navigation.