No, I don't suppose it is 'the' way to do this - it's too weird to have to create a page only to remove it again - just to get rid of the parent as wel. But it did work and I hadn't found another way yet... :-)

Ok, to be complete - feeling a bit guilty I guess :-( : the preferred way would probably be to use the canCreate() method. Just adding it to your custom MyPage class and having it return false, would remove it from the dropdown:

class MyPage extends Page {

	function canCreate($Member = null) {
		return false; 
	}
	...

Because this would now prevent any user, even the admin, from creating a page of this type, you'd need to build in some conditional. One way to do this, is to create a new permission code within the SecurityAdmin, and check that against the current user.

Check out http://www.ssbits.com/snippets/2009/create-a-permission-code/ for how to create and work with permissions.

I experimented with a (simple) bit of code, where you can define a list of 'restricted' pagetypes using an array from _config.php. If anyone is interested, I'll add a link...

I created a ProtoPage that extends SiteTree and altered Page to extend from ProtoPage. This allows me to put all base functionality in ProtoPage.

To stop ProtoPage from showing up in the new menu, add the following line to mysite/_config.php (SS 3.0.5):

SiteTree::$hide_ancestor = 'ProtoPage';

Note it's not good practice to set variables directly, but there is no set_hide_ancestor. I assume it's recommended to set the hide_ancestor attribute on individual page types, however you then have to ensure that any page type that inherits sets the value back to the value in SiteTree (null).

Not sure if this will come in handy for anyone but I came across this post researching this issue for myself and thought I would share.

	function canCreate($Member = true) {
		if( DataObject::get('PageTypeClassName')->count() == 0 ){
			return true;
		}
	}