Google Knows You

I am very impressed that Google is going to allow users access to their 'profile' they put together to target ads to them. You can even add interests that Google has not picked for you yet!

http://www.nytimes.com/2009/03/11/technology/internet/11google.html

We have built a tool called Ads Preferences Manager, which lets you view, delete, or add interest categories associated with your browser so that you can receive ads that are more interesting to you.

From the horse's mouth - http://googleblog.blogspot.com/2009/03/making-ads-more-interesting.html

For the record, I do agree with Google, more relevant ads are much more interesting for me. I love free/ad supported software/content and I hope the business model continues to work.