While experts have gone back and forth about the potential health risks of cell phones since, well, about the time they became widespread - a recent European study suggests people using cell phones for 10 or more years have a higher risk of developing brain tumors than do non-cell phone users. The five-nation study involving more than 4,500 people found a statistically significant increase in the incidence of tumors on the side of the head where the users hold their cell phones.
My suggestion is to get a hands free headset, which will free up your hands and make multitasking while talking on the phone easier and safer and perhaps, reduce your risk. The Motorola H500 Bluetooth Headset for all Bluetooth Enabled Phones  is a hit with crowds, but if you are still skeptical of the risks of using Bluetooth, check out a much cheaper - and potentially safer- option like the Motorola Hands-free Headset for RAZR , which is on sale on Amazon for $.99. You can get a headset at any cell phone or electronics store, just make sure it fits your phone.