Sometimes it is useful/interesting to have a look what's inside a .wba file (e.g. fonts, wallpaper, etc) before installing it.
Try putting a shortcut to WinZip in your SendTo folder. Then you can right-click on a .wba file and select Send To > WinZip. The same trick will work for a lot of skin files which are really just renamed .zip files e.g. .obtheme, .ip, etc.