Do cell phones cause cancer?
As a physicist, I am tempted to answer "Hell no!"
Microwave radiation is a million times too weak, in terms of energy per photon, to split chemical bonds and thereby cause mutations in DNA molecules. It's hard to imagine any other mechanism by which microwaves from cell phones could hurt anyone.
That said, I can't really prove that cell phones are safe. It's really hard to prove that anything is perfectly safe. But that doesn't stop scientists from trying. Here is an abstract from the article "Mobile Phones, Brain Tumors, and the Interphone Study: Where Are We Now?" by Anthony J. Swerdlow, Maria Feychting, Adele C. Green, Leeka Kheifets, David A. Savitz in the journal Environmental Health Perspectives describing the most recent research on this topic:
Background: In the past 15 years, mobile telephone use has evolved from an uncommon activity to one with > 4.6 billion subscriptions worldwide. However, there is public concern about the possibility that mobile phones might cause cancer, especially brain tumors.
Objectives: We reviewed the evidence on whether mobile phone use raises the risk of the main types of brain tumor—glioma and meningioma—with a particular focus on the recent publication of the largest epidemiologic study yet: the 13-country Interphone Study.
Discussion: Methodological deficits limit the conclusions that can be drawn from the Interphone study, but its results, along with those from other epidemiologic, biological, and animal studies and brain tumor incidence trends, suggest that within about 10–15 years after first use of mobile phones there is unlikely to be a material increase in the risk of brain tumors in adults. Data for childhood tumors and for periods beyond 15 years are currently lacking.
Conclusions: Although there remains some uncertainty, the trend in the accumulating evidence is increasingly against the hypothesis that mobile phone use can cause brain tumors in adults.
Read more:
http://ehp03.niehs.nih.gov/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1289%2Fehp.1103693
I would draw a somewhat stronger conclusion:
Cell phones can't hurt you, just as the 60-Hertz radiation from power lines can't hurt you.
= new reply since forum marked as read
It lets me charge my electric car at lower rates from midnight to 6 AM. 
Best abstract ever written. 
Response to Lionel Mandrake (Original post)