http://picasa.google.com/

This free desktop photo management software from Google provides a fantastic way to manage a large photo collection. It incorporates basic editing tools, and makes it easy to open a file in a more advanced application (such as the GIMP). It’s integration with Google’s online web album system makes sharing images and video with friends and the general public a breeze.  One nice feature is that it allows you to share files under Creative Commons licenses, which are subsequently shown in Google Images searches.