If you're looking for a powerful FTP client that allows you to administer it from wherever you are, then CrushFTP could be your answer.
CrushFTP handles just about every protocol out there, including SFTP (SSH FTP), FTPS (FTP over SSL), HTTP, HTTPS, WebDAV, and WebDAV SSL, which makes it a highly secure client. CrushFTP derives its name from the way it compresses transfers on the fly, conveniently removing the need for a compression tool before transferring. The best news for those seeking remote access, however, is that CrushFTP features an easy to use web client that allows anyone to upload files to your server wherever they are. This web client even supports drag and drop, transfer resuming after broken transfers and a web upload manager that details the progress of each action. When a user has uploaded a file, the administrator will be notified by email when it's complete, or you can opt to receive just one email detailing the user's uploads throughout the day.
CrushFTP is even expandable via plug-ins, such as a web stats plug-in, an auto-unzipper and a file filter for only allowing files with certain extensions to be uploaded. Despite all this functionality however, CrushFTP's interface leaves quite a bit to be desired. It looks like the developer has just taken the Windows version and translated it directly to OS X, which is never a good idea. The web interface is much better though, and it's a shame the developer didn't use more of that look on the client itself.
That said, CrushFTP is a very secure and powerful FTP client that will appeal to advanced users and those in need of web client functionality.
- Many fixes and features which can be found here: http://crushftp.blogspot.com/2010/10/crushftp-550-released-this-is-big.html