Has anyone been able to get SHGetFolderLocation to work? i see plenty of
posts about people having problems with it, and one fellow saying it is not
possible to use under .NET.

For me it returns 0x80070057 "The parameter is incorrect"

using System;
using System.Runtime.InteropServices;
using System.ComponentModel;
class TestApp
{
   public static void Main()
   {
       Int32 nToken = 0x000c; //CSIDL.CSIDL_MYDOCUMENTS;
       IntPtr pidl = IntPtr.Zero;
       Int32 result;

       result = SHGetFolderLocation(
               IntPtr.Zero, //hWnd
               nToken, CSIDL
               IntPtr.Zero, //Access Token
               0, //reserved
               out pidl);

       Console.
       if (result < 0)
       {
           throw new Win32Exception(result);
       }
   }

   [DllImport("shell32.dll", EntryPoint = "SHGetFolderLocation",
SetLastError = true,
           CallingConvention = CallingConvention.StdCall)]
   public static extern Int32 SHGetFolderLocation(
       IntPtr hwndOwner, //hWnd
       Int32 nFolder, //CSIDL of folder
       IntPtr hToken, //Access token
       UInt32 dwReserved, //Zero
       out IntPtr pidl);

   [FlagsAttribute]
   public enum CSIDL
   {
       /// <summary>
       /// Version 6.0. The virtual folder representing the My Documents
desktop item.
       /// This should not be confused with CSIDL_PERSONAL, which
represents the file system folder that physically stores the documents.
       /// </summary>
       CSIDL_MYDOCUMENTS = (0x000c)
   }
}