Xfolders 1.1 is a Mac OS X file manager that displays two directories at once in side-by-side panes and provides Norton Commander-style keyboard operation as well as drag-and-drop and menu commands. Along with move/copy/delete/rename, it provides control of file and folder permissions, bookmarks and a bookmark manager for folders, Finder integration, intelligent path navigation, toolbar access to system utilities, and other features. This release adds an integrated Spotlight search, more versatile search and compare options, support for zip/unzip, faster copying, and other improvements. Xfolders is free for Mac OS X 10.4.The author's web site has a screen shot that shows the same function keys I remember from the original Norton Commander. NC/DOS was one of the best products I've ever used on any platform -- a true classic. I used FileCommander for OS/2 for a while, it came close. This app is pretty new, so it's worth checking out the versiontracker and macupdate responses. Too bad this German company doesn't have an XP version.
I'll give it a try and update this post with what I learn.
Update 2/24/06: I tried it and it wouldn't launch. I suspect it wants to run in admin mode; I always run in regular user mode. Deleted immediately. If an OS X application won't run in user mode then there's a very high probability that it's junk.