A widget that only show to users who are logged out?

Yes, this is possible with a small widget customization. For example, the following widget script will hide the widget if the accessing user is registered (logged in).

#set ($isCurrentUserRegistered = $core_v2_user.IsRegistered($core_v2_user.Accessing.Id))
#if ($isCurrentUserRegistered)
	$core_v2_widget.Hide()
#end

<div>Content that should only be shown to non-registered users</div>

Slight correction in your IF statement.. it should have a not in there..

#if (!$isCurrentUserRegistered)

In Michael's example he was hiding the widget for registered users and showing the content only to anonymous users.  The logic could of course be reversed to hide the widget from anonymous users.

Ohh, thanks, I got blinkered by the use-case I had in mind

Thanks Michael that's really helpful

Chris