I wouldn't be surprised if future versions of iPhone had a (mini?) Thunderbolt "docking" port, which can even support external graphics cards (http://www.macrum

I wouldn't be surprised if future versions of iPhone had a (mini?) Thunderbolt "docking" port, which can even support external graphics cards (http://www.macrumors.com/2013/07/30/11-macbook-air-owner-connects-high-end-graphics-card-with-complex-thunderbolt-setup/ http://www.macrumors.com/2013/07/30/11-macbook-air-owner-con...). And CPUs can throttle their speed or disable cores depending on desired power consumption, of course. Heat dissipation could probably be solved with a metal back plate. RAM seems like the only major issue for a iPhone-based desktop/laptop. Not sure if RAM expansion via Thunderbold is feasible.