> Therefore any piece of Linux software.. whether it's drivers, games, or applications, absolutely must provide their own out-of-band solution for providing binaries if they expect Linux users to use it any time in the next six-eight months. Any distribution supported scheme is going to be distribution and release-specific.
> Unfortunately none of the solutions application developers come up with are really that good.
http://0install.net is designed to address this problem. It downloads tarballs (source or binary), manages multiple versions, uses GPG signatures, handles shared libraries, and supports dependencies downloaded itself or from the distribution (if sufficiently up-to-date) using PackageKit.
It's also included in most distribution repositories already (as the zeroinstall-injector package): Debian, Ubuntu, Fedora, OpenSUSE and Arch, at least. And it also works on Windows and Mac OS X.
I haven't seen it used for GNOME, but e.g. on most distributions you can run the ROX desktop's file manager like this: