aspx page to redirect to a new page

You could also do this is plain in html with a meta tag:

<html>
<head>
  <meta http-equiv="refresh" content="0;url=new.aspx" />
</head>
<body>
</body>
</html>

Darin's answer works great. It creates a 302 redirect. Here's the code modified so that it creates a permanent 301 redirect:

<%@ Page Language="C#" %>
<script runat="server">
  protected override void OnLoad(EventArgs e)
  {
      Response.RedirectPermanent("new.aspx");
      base.OnLoad(e);
  }
</script>

<%@ Page Language="C#" %>
<script runat="server">
  protected override void OnLoad(EventArgs e)
  {
      Response.Redirect("new.aspx");
  }
</script>