If your goal is to be able to transfer files no matter what machine you are on, learn to use the DOS and linux command line ftp clients. You should use the ones that are already provided by the system. They will usually be available to you. You may not always be able to download CuteFTP every time you are at a new machine.

If you type ftp://username:[email protected]/ into your browser, you will only be able to download files, not upload them. Also, be very careful doing this, because your password will be stored in the browser's history. Anyone can read the history, and use your username password to gain access to your system.

Edit: Minor formatting changes.