Free FTP Software makes Uploads and Downloads a Snap! CoffeeCup Free is a fast no frills FTP program that makes it easy to drag and drop files to your website. It supports multiple server profiles,...? http://www.coffeecup.com/freestuff/
Core FTP Lite is a Windows FTP client that supports uploading/downloading/deletion of directories (folders) and files, browser integration, SFTP (or secure FTP), SSL/TLS, handling of file permissions, transfer bandwidth control, etc http://www.coreftp.com/
FileZilla is a free, open source FTP / SFTP Client for Windows, Linux and Mac OS X distributed under the GNU General Public License. You can do the usual stuff, upload and download files, as well as resume uploads or downloads, works with firewalls, supports SFTP (Secure FTP) and SSL secured connections, handle queues of files to be uploaded/downloaded, etc. At the time this was written, the Linux and Mac OS X versions are under Beta testing. http://www.filezilla-project.org/
OneButton FTP is a graphical FTP client for Mac OS X using the Cocoa framework. According to the website, it "will have a strong emphasis on drag and drop usability and file queuing". It is licensed under the GNU General Public License. http://www.onebutton.org/
Cyberduck is an open source FTP and SFTP browser for Mac OS X. It supports drag and drop, resuming of uploads and downloads, synchronisation of files on a local computer with a server, uploading and downloading of folders, etc. It is licensed under the GNU GPL. http://www.cyberduck.ch/