It's an 'empty' app, I guess, with the icon of the separator.
To prevent anything to happen when clicking on them, use the dev tools' SimpleText and put the Icon as simpletext.icns in the Resources folder. Delete everything else from the package. Then rename the application ' .app' ('space'.app) so no name shows up when moving over the tile.
Uses a whole tile-space, though, as you can see from his desktop screenshot.
To prevent anything to happen when clicking on them, use the dev tools' SimpleText and put the Icon as simpletext.icns in the Resources folder. Delete everything else from the package. Then rename the application ' .app' ('space'.app) so no name shows up when moving over the tile.
Uses a whole tile-space, though, as you can see from his desktop screenshot.