Here's a video showing the new features I've added to my bhGhost tool (original short video here vimeo.com/49638174) and showing some typical workflows and uses of it.
UPDATE December 2012 - I've added a new feature to make this much faster to set up for multiple characters, check that out here - vimeo.com/55820912
The script is now available to download from my site here - graphite9.com/MayaDownloads.html
Hope you enjoy it.
NB - One thing I didn't mention in the video (it's mentioned in the built-in Help though) is that the tool currently only works with regular mesh objects (which 99% of characters usually are). If you have Nurbs eyes in the rig they can't be ghosted so don't add them to the Meshes list as they will cause an error (you can just remove them from the list though if that happens and the tool will work again). I've tested the tool with pretty much every character rig I have here and it works with all of them.
Update 10102012 - I've added a new feature to the tool so there's an update available, you can see that here vimeo.com/51152705