look here in this forum (http://moodle.org/course/view.php?id=32).
I can tell you something about moodle in german companies. There is a call center training all members all the time with moodle. There are lots of great companies realising vocational training with moodle and last I heard from an financial network with some 10.000 members and moodle.
Most of the companies use moodle in their intranet. So moodle isn't visible for visitor and the system isn't listed at moodle sites.