I don't think this is a good idea.  It will take you back to the **start** of the presentation.  Just hitting the "Back" button should take you back to the slide you were on.  So giving people this option actually seems like a bad idea.

I *think* that making the href `javascript:history.back()` will effectively transform this into the "Back" button, BTW.  But I haven't tested it yet.  But that seems far superior to `/`.

Comments?