While I go back and forth, I tend to agree that once you get beyond the short term release of endogenous opioids in response to the expectation of pain relief, a mysterious placebo effect that produces all sorts of miraculous effects is far less proven than people think.
Robert K. Adair who is professor emeritus of physics at Yale points out that the energy from a cell phone is simply too low in comparison to the endogenous energy of the molecules in the cells in our body to possibly have any effect.