I found this plugin in a search, it is just what I wanted so I downloaded it, clicked 'network activate' and my site disappeared. Front end and back end are blank. I've re-loaded, re-booted and all that - I get nothing. I'm running this on a test site with up-to-date PHP (5.4) and a Rocket Theme Gantry template. Everything has been working fine for about a month, until now.
Link is http://www.vibrations.ca/vibrations_wp