gdebi is a simple to tool install local deb files or install the build-dependencies of .dsc files. It will use apt to figure if the dependencies can be satified and what additonal software is required. It needs a vte and recent python-apt to work. vte needs a patch to make it not close file descriptors, python-apt needs some new features. It will need root to install the deb, and it has a non-root non-root bit to view the deb and a "non-interactive" bit that is exec()ed with pkexec.