Right click, "Arrange Icons By", "Show In Groups."
If you display the folder by details, it will organize by the header you click on. Like if you click on "Name" it will organize by name.
If you're grouping by something that it doesn't have, it will probably display "unspecified"
http://support.microsoft.com/default.aspx?scid=kb;en-us;306554&sd=tech