Indeed, few people actually think of sunlight as being harmful, which it is. The sun emits quite a bit of nasty stuff from UV rays to xrays, gamma rays, and beyond! The most harmful being the UV rays since they are present at much greater levels. All of that is ionizing radiation.
How many of those who believe cell phones cause cancer step outside on a sunny day without any sunscreen lotion? I'm willing to bet quite a few.
A few hours in the sun with no sunscreen lotion probably increases your cancer risk by a lot more than a lifetime's worth of cellphone usage (that's assuming cellphone microwave radiation has any effect at all whatsoever).