Perhaps like http://www.bitcointrezor.com/ - a keychain fob which lets you pay and recieve bitcoin safely, even on infected computers, as the private key never leaves the device.

Bitcoin's in its infancy so people currently using it are doing so 'on the metal', but the system is flexible and user friendly layers will be built with time.

Also, reversible payment networks can be built on top of a non-reversible-payment foundation, but not the other way around.