Despite the inflammatory headline from this article in the Globe and Mail, a closer inspection of the results of a new study suggests that researchers are still not able to conclusively link cell phone use to brain cancer. But the researchers think that further investigation is warranted, given the risks involved and the huge increase in cell phone use since they collected the data for their study.
Many studies have been conducted on this issue over the years. The results have been mixed. Many countries have issued explicit warnings that people should be cautious about excessive use of cell phones, especially by minors whose physiology is not fully developed yet, but Canada has no such regulations.
Personally, I try to minimize my exposure to cell phones, including the Blackberry I use for work. I keep it off 95% of the time and only place a call in case of extreme necessity. Better safe than sorry.