I had a request to exclude items contained in the approval tasks list from appearing in SharePoint's search results. At first glance it could be as simple as making changes to the lists properties (List Settings -> Advanced Settings) to explicitly exclude it from appearing in search results. This would work if you only had a few lists to update, but lets say, that like me, you had well over 100 lists to update....You could develop a utility that makes use of SharePoint's API to update the list, ......