Now you might also see a small message next to the snippet which explains that the result was picked because you've searched for a different keyword before. For example, if you search for [tablet] and then search for [asus] Google will include some tablet-related search results and even highlight a page about the Asus Transformer. Right now, this feature is only available in the US.
Sometimes this could be useful. Google connects the dots and tries to provide better results by using keywords from your previous searches. But that's not always a good idea because two consecutive queries aren't necessarily related. You could search for [html table] and [blackberry] and the second result for [blackberry] will be:
Google's algorithms aren't perfect and Google should provide an obvious way to hide the "enhanced" results. You can scroll to the bottom of the page, click "view customizations" and then click "without these improvements", you can also "disable customizations based on search activity" if you aren't logged in, but these options are cumbersome.
{ Thanks, Nick. }