Now the new study claims that there is no cancer link, but at the same time finds that
A significantly increased risk was found for tumours which developed on the same side of the head as the phone was reported to have been held but this was mirrored by a decrease in the risk on the opposite side of the head making it difficult to interpret as a real effect.from http://www.sciencedaily.com/releases/2006/01/060119232625.htm
This finding may be due to people with glioma brain tumours linking mobile phone use to the side of the tumour and therefore over reporting the use of a phone on the same side as their tumour. This results in under reporting use on the opposite side of the head, say the authors.
On balance it looks to me like we have even more uncertainty about mobile phone safety than before.