
It is not fashionable nowadays to speak of the merits of the command line, in an age where things like streaming video and Aqua are an integral part of our daily life. However, I do not think that typed-in commands must necessarily be consigned to the dustbin of computer history. Of course, I am not suggesting that we all drop X and Windows and pretend like we are living in the early eighties. The command line interface still has much to offer us, and many of its benefits simply cannot physically be emulated or even replaced by graphical ones.
I was always a huge fan of Directory Opus back on the Amiga. It was a GUI file manager that allowed a huge degree of customization -- you could edit/create your own buttons, which performed CLI commands on files selected via the two-pane GUI - thus giving you the power of the command line (minus a bit of flexibility, as you had to open the config and make a new button to use a different command) with the speed and intuitiveness of a GUI. There's a similar Linux-based file manager called Gentoo, but it's a bit weak in comparison.
I always thought this design could be vastly improved by the addition of a command line window to the GUI, though. Type in a one-off command to run it on the fileset selected in one of the panes, or right click a button and have its command dropped into the command window so you could add some extra parameter or something.