Windows/Mac/Linux: If you're not a fan of your system's tools for managing files on your computer, check out MuCommander. The free, open source download will run on nearly any operating system, including Windows, Mac OS X and your favorite flavor of Linux, and in 21 different languages. Drag and drop between two panes visually, or hack away in the command shell. It also supports most network file transfer protocols, such as FTP, and will even let you browse the contents of archives like ZIP and disk images like ISO without having to uncompress or mount them, respectively. Pictured is an image file viewed directly from an SFTP server — handy! MuCommander is a free download for all platforms.
MuCommander [via Download Squad]