Simplifies FTP access (slightly) by wrapping the system.net.ftpWebRequest class methods:-

Code:
using System;
using System.Net;

namespace FileTransfers
{
    /// <summary>
    /// Class to facilitate sending and receiving files by FTP
    /// </summary>
    public static class FTPFileTransfer
    {

        /// <summary>
        /// Uploads the named file to the FTP target site
        /// </summary>
        /// <param name="filename">The file to send to the FTP site</param>
        /// <param name="address">The address of the machine and folder to send the file to</param>
        /// <param name="ftpUsername" >The user name to connect to the FTP target as</param>
        /// <param name="ftpPassword" >The password to connect to the FTP target with</param>
        /// <returns >
        /// True if the file was succesfully uploaded, otherwise false
        /// </returns>
        public static bool FTPUploadFile(System.IO.FileInfo filename,
                                   string address,
                                   string ftpUsername,
                                   string ftpPassword)
        {

            bool _uploadSucceeded = false;
            byte[] buf = new byte[2048];
            int iWork;
            System.Uri _targetURI = new System.Uri("ftp://" + address + @"/" + filename.Name);
            FtpWebRequest req = (FtpWebRequest)FtpWebRequest.Create(_targetURI);
            req.Credentials = new NetworkCredential(ftpUsername,
                                                 ftpPassword);

            System.IO.Stream rs = null;
            System.IO.FileStream fs = null;

            req.UsePassive = false;
            req.KeepAlive = false;

            req.Method = WebRequestMethods.Ftp.UploadFile;
            try
            {
                rs = req.GetRequestStream();
                fs = System.IO.File.Open(filename.FullName, System.IO.FileMode.Open);
                while ((iWork = fs.Read(buf, 0, buf.Length)) > 0)
                    rs.Write(buf, 0, iWork);
                if (rs != null)
                {
                    rs.Close();
                    rs.Dispose();
                }
                FtpWebResponse wrRet = ((FtpWebResponse)req.GetResponse());

                if (wrRet.StatusCode == FtpStatusCode.CommandOK || wrRet.StatusCode == FtpStatusCode.ClosingData || wrRet.StatusCode == FtpStatusCode.ClosingControl || wrRet.StatusCode == FtpStatusCode.ConnectionClosed || wrRet.StatusCode == FtpStatusCode.FileActionOK)
                {
                    _uploadSucceeded = true;
                }
                else
                {
                    System.Diagnostics.Trace.TraceError(string.Concat(filename.FullName, " ftp status  code: ", wrRet.StatusCode.ToString()));
                    _uploadSucceeded = false;
                }
                wrRet.Close();
            }
            catch (System.Exception ex)
            {
                System.Diagnostics.Trace.TraceError(ex.ToString());
                _uploadSucceeded = false;
            }
            finally
            {
                if (fs != null)
                {
                    fs.Close();
                    fs.Dispose();
                }
                if (rs != null)
                {
                    rs.Close();
                    rs.Dispose();
                }
            }
            // Return the FTP process status to the caller
            return _uploadSucceeded;
        }


        /// <summary>
        /// Downloads a named file from the FTP directory
        /// </summary>
        /// <param name="targetFile">The filename on the FTP site</param>
        /// <param name="sourceFileName">The filename to save it as locally</param>
        /// <param name="address">The address of the machine and folder to get the file from</param>
        /// <param name="ftpUsername">The user name to connect to the FTP target as</param>
        /// <param name="ftpPassword">The password to connect to the FTP target with</param>
        /// <returns></returns>
        public static bool FTPDownloadFile(System.IO.FileInfo targetFile,
                                   string sourceFileName,
                                   string address,
                                   string ftpUsername,
                                   string ftpPassword)
        {
            bool _downloadSucceeded = false;
            byte[] buf = new byte[2048];
            int iWork;
            System.Uri _targetURI = new System.Uri("ftp://" + address + @"/" + targetFile.Name);
            FtpWebRequest req = (FtpWebRequest)FtpWebRequest.Create(_targetURI);
            req.Credentials = new NetworkCredential(ftpUsername,
                                                 ftpPassword);

            System.IO.Stream rs = null;
            System.IO.FileStream fs = null;

            req.UsePassive = false;
            req.KeepAlive = false;

            req.Method = WebRequestMethods.Ftp.DownloadFile;
            try
            {
                FtpWebResponse wr = (FtpWebResponse)req.GetResponse();
                rs = wr.GetResponseStream(); 
                // Read the request stream into the target file
                fs = System.IO.File.Open(sourceFileName, System.IO.FileMode.Create);
                while (((iWork = rs.Read(buf, 0, buf.Length)) > 0))
                    fs.Write(buf, 0, iWork);
 
                if (rs != null)
                {
                    rs.Close();
                    rs.Dispose();
                }
                // Make sure the file is fully written
                fs.Flush();

                FtpWebResponse wrRet = ((FtpWebResponse)req.GetResponse());
                if (wrRet.StatusCode == FtpStatusCode.CommandOK || wrRet.StatusCode == FtpStatusCode.ClosingData || wrRet.StatusCode == FtpStatusCode.ClosingControl || wrRet.StatusCode == FtpStatusCode.ConnectionClosed || wrRet.StatusCode == FtpStatusCode.FileActionOK)
                {
                    _downloadSucceeded = true;
                }
                else
                {
                    System.Diagnostics.Trace.TraceError(string.Concat(sourceFileName , " ftp status  code: ", wrRet.StatusCode.ToString()));
                    _downloadSucceeded = false;
                }
                wrRet.Close();
            }
            catch (System.Exception ex)
            {
                System.Diagnostics.Trace.TraceError(ex.ToString());
                _downloadSucceeded = false;
            }
            finally
            {
                if (fs != null)
                {
                    fs.Close();
                    fs.Dispose();
                }
                if (rs != null)
                {
                    rs.Close();
                    rs.Dispose();
                }
            }
            // Return the FTP process status to the caller
            return _downloadSucceeded;
        }
}