I grew up without cell phones and I would like my children to grow up the same. Sadly the technology is required these days, but on the other hand, the frequencies of cell phones - however low - they will always be damaging to ourselves, especially children who are much softer.
The thing with technology is that has a lot of variations and levels of waves. Most cell phones do not emmit harmful radiation, just thermal radiation, which in turn creates free radical roots in our brain cells and thus cancer.
The simple answer is both. The minimum distance, for prolonged exposure is 50cm. So, when you sleep and have it for alarm clock, it is better to be more than a hand's reach (A grown up arm reach is aproximatelly 50-75cm) . When you have in on your ear and talking, the thermal radiation is much more than the EM radion that the phone produces.
Also doctors suggest to have it far from vital organs, just to be sure. 10cm of human tissue are dense enough to counter the EM radiation. So, not near brain, heart, liver and genitals.
We are being bombarded by wifi, cell phones and other radiation from sources that can have a impact on our daily lives and our health. Cell phones are becoming more powerful so that they can do more. How is the human body responding to this? Are we forcing a change in the human body to cope with all this new bombardment of electronic impulses? I do wonder what is the long term effect on us from all of this.