New Debian Project Wants To Hardened Debian For Desktop Users
The aim is to have an encrypted root file system and using virtualization technology to put each program in a sandbox.
Furthermore, they want to educate the user by giving warnings or guides how to securely life in the digital world.
An easier approach is doing the gentoo community by offering the hardened gentoo project.
An other but "looking like it is working" project is the qubes os. Basically, they are putting everything in a virtual application on top of a xen hypervisor. With some nice ideas, they are dealing with the speed als well as the consumed space of each "app". Qubes os is based on fedora.