Perhaps a peltier device with bluetooth connectivity to monitor battery temperature to maintain temperature at the appropriate level.-- lostmind, Dec 09 2013 Or, a motorized tether which twirls the phone at high speed-- sninctown, Dec 09 2013 Or a satellite updated series of catchers and slingshots that has cellphones flying above us.-- lostmind, Dec 09 2013 The device could be in the form of a tall chrome plated pedestal that sweats beads of evaporation from its icy-cool surface.-- pocmloc, Dec 09 2013 Or an air-hockey table that lets the phone drift around a little.-- baconbrain, Feb 25 2015 random, halfbakery