I’m glad you like the plug-in 🙂
EO doesn’t support ‘hidden’ event categories, however, it should work with most plug-ins that allow you to restrict content.
Alternatively you could use a bit of custom code to exclude a certain category from all queries (see https://gist.github.com/stephenharris/5600396).
You can use the shortcodes to include a specific category – in particular the event list (shortcode and widget) and fullCalendar shortcode (see these links: http://wp-event-organiser.com/documentation/shortcodes/ ). Unfortunately this is not available the agenda widget.
Event Organiser Pro has been available for just over a month now :).
I had in mind: http://wordpress.org/extend/plugins/members/ when I mentioned content restriction plug-ins, but I’ve never tested it…
Thanks Stephen, I will play around with the github example code!
Chris