The BetterStreams Library

using System;
using System.IO;
using BetterStreams;

namespace BetterStreamsExamples
{
    static class CopyExample
    {
        public static void CopyADS(string filename, string targetDirectory)
        {            
            //get a list of all the alternate data streams in the file
            long[] streamLengths;
            string[] streamNames =
                AlternateStreams.GetStreamNames(filename, out streamLengths);

            //4KB buffer used to transfer data
            byte[] buffer = new byte[4096];

            //copy each stream's contents into a new file
            //(an exception will be thrown if any target files already exist)
            for (int i = 0; i < streamNames.Length; i++)
            {
                string targetFile = Path.Combine(targetDirectory, streamNames[i]);
                
                AsyncStream source =
                    new AsyncStream
                    (
                        AlternateStreams.OpenStream(filename, streamNames[i]),
                        AsyncStreamMode.Reading,
                        1024 * 50 //50KB buffer
                    );

                AsyncStream target =
                    new AsyncStream
                    (
                        new FileStream(targetFile, FileMode.CreateNew),
                        AsyncStreamMode.Writing,
                        1024 * 50 //50KB buffer
                    );

                target.SetLength(streamLengths[i]);                
                
                //copy
                int readBytes;
                while ((readBytes = source.Read(buffer, 0, buffer.Length)) > 0)
                    target.Write(buffer, 0, readBytes);

                source.Close();
                target.Close();
            }
        }
    }
}