The bretteleben.de "Weblinks with Thumbshots" component for Joomla! 1.5 modifys the default Joomla! component "Weblinks" and replaces the default icons with thumbshots (preview images) of the linked website. The link to your thumbshot provider is set in the backend of the default "Weblinks" component. Why a core hack instead of a separate component? The modification concerns only 3 files of the original component and this is - in my opinion - no reason to reinvent the complete component. In addition - this way allows to go on using the already existent links and takes just a few clicks to install/uninstall.