Gentoo Linux and Portage
I haven't used any of the BSD's all that much (a little bit of OpenBSD here and there but thats about it) so I don't know a whole lot about the ports tree, but I believe Gentoo Linux has something very similar to it called Portage... its basically a cvs tree containing scripts pointing to the locations of various programs and also containing installation and dependancy information and all that. You can rsync your local tree to the central one, and whenever you like just rebuild one of the programs for which there is a script in the tree. It will then download all of the necessary sources, compile and install everything for you, and then store configuration information (sorta like rpms or debs once they are installed). You can uninstall the installed program just as easily. It may not be exactly what you are thinking of, but its definately worth checking out. http://www.gentoo.org.