This Dr. Jonathan Samet Talks About Cancer and the Environment – NYTimes.com is a profile of Dr. Samet, the head of the International Agency for Research on Cancer report that put cellphones in the “possibly carcinogenic” category. I’ve read other articles on this report and found their conclusions very doubtful – particularly since the effect size is almost infinitesimal. I would find it far more likely that anyone who spent hours a day on a cellphone over a decade has a mental health issue. The possibility of non-ionizing radiation causing a inflammatory reaction in the brain is interesting, but the sample size was very small.
My basic concern with the cellphone / cancer link is that humans have been exposed to all sorts of non-ionizing radiation much more powerful than a cell phone for almost a 100 years. For instance, a hair dryer would expose you to far much more of this radiation targeted at the head. There are no reports of such a link in this case.