SF project page
Start the client here if you have Java 1.5 installedPatchEditor is a A simple easy-to-use application for "visually editing" of large patch files (diff files); different patches/diffs/folders/files can be selected/deselected, the resulting patch file can be saved and/or run against a source tree (e.g.).
But of course, we all know you're here for the screenshots. Here is the best we have: