Save Album Art to Album Folder will export the artwork of the selected tracks or tracks in the selected playlist as a graphics file to the folder which contains each selected tracks fileor a specific user-selected folder.
Save Track Art to Album Folder exports the artwork of the single selected track to its parent folder, replacing any previous version.
The ReadMe explains much more, including modifications you can easily make.
This latest version updates syntax for compatibility with Snow Leopard, streamlines some code, provides new bundled progress indicator app.