Are cell phones harmful to your health?

Larry King Live is airing a segment on the death of an attorney who had a brain tumor some say is highly correlated to cell phone use. The show will air Tuesday night at 9pm. 

The controversy is so strong around this issue, some countries have laws in place that are stricter than the U.S. in terms of where cell phone towers can be placed. Case in point: Israel.

Do you think cell phones can cause brain tumors and other cancers because of their proximity to the body? Would cell phone use, then, be harmful to a pregnant woman and her unborn child if she was using a cell phone with a hands-free set, but the cell phone itself was always in a holster at her hip or in her coat pocket? Is it the transmission from the RF waves, or something else?