How about Qubes OS? http://qubes-os.org/trac
Invisible things is awesome, they're right up front too. Outside of the mainstream players my claim isn't worth much.
You can do some of this with VM's, Build a machine, use it for web access, delete it when done. With a carefully constructed virtual drive, you can just clone the drive, start the machine, discard when done. Not at all a "friendly" way to go but one which adds another layer to the puzzle for your attacker.
Chrome OS is probably the only commercial platform that is designed with this era of threats in mind. It's at least a generation ahead of everybody else. They're actually building their own embedded controller (controls the fans, battery etc.) to go along with their open source firmware so they can worry less about bad guys in the supply chain.