PageContentItemsService.cs

    public class PageContentItemsService
    {
        public readonly ID PageContentItemFolder =
            new ID(ItemTree.Templates.Site.PageContentItems.Id);


        public bool IsPageContentItemsFolder(Item item)
        {
            return item.TemplateID == PageContentItemFolder;
        }

        public bool ShowPageContentItems
        {
            get { return Registry.GetBool("/Current_User/UserOptions.View.ShowPageContentItems", false); }
            set { Registry.SetBool("/Current_User/UserOptions.View.ShowPageContentItems", value); }
        }
    }