Plone provides "Live Searching" out-of-the-box. This means Plone searches as you type, the same way you may have experienced with Google, making it wasier to find what you are looking for faster. Search results are also available as an rss 1.0 feed enabling you to customise content you are interested in syndicating.

Example below.

For more information about live search see http://plone.org/documentation/whatsnew/2.1/livesearch