Hiding Html.ActionLinks based on Role-based security
@section Contextual {
  <div>@Html.ActionLink("Create New", "Create")</div>
  <div>@Html.ActionLink("Generate Report", "Report")</div>
  <div>@Html.ActionLink("Other Stuff", "Other")</div>
}

[Authorize(Roles = "Editor")]
public ActionResult Create()
{
   // stuff
}

@section Contextual {
  @if (User.IsInRole("Editor"))
  {
     <div>@Html.ActionLink("Create New", "Create")</div>
  }
  <div>@Html.ActionLink("Generate Report", "Report")</div>
  <div>@Html.ActionLink("Other Stuff", "Other")</div>
}

// on the controller
 viewModel.CanCrete = User.IsInRole("Editor");
 // ...snip...
 return View(viewModel);
}

public static string If( this string s, bool condition )
{
  return condition ? s : String.Empty;
}

@section Contextual {
  <div>@Html.ActionLink("Create New", "Create").If(Model.CanCrete)</div>
  <div>@Html.ActionLink("Generate Report", "Report")</div>
  <div>@Html.ActionLink("Other Stuff", "Other")</div>
}