Note: Although it is true that cell phones emit low frequency magnetic fields that can be measured in milliGauss, they also emit high frequency microwave radiation which is what all the concern (and publicity) is about, and which the products below are designed to shield. Many clients have contacted us seeking a shield for BOTH magnetic fields and microwaves for their phone. Such a shield does not currently exist. To reduce your exposure to BOTH types of radiation, use an airtube headset and keep the phone itself at a distance.
Until the FCC establishes testing procedures that fully correspond to real-world cell phone use and reviews its radiation standards to ensure that they are fully protective for all users, including young children, EWG advises phone users to adopt these simple measures to minimize radiation exposure: Use a headset, keep the phone away from the body and text rather than talk.  
The electromagnetic spectrum is broken up into two parts based on whether small doses of that radiation can cause harm: ionizing radiation and non-ionizing radiation. Ionizing radiation—UV, x-rays, and gamma rays—has enough energy in one photon (quantized minimum packet of light) to remove electrons from atoms or break apart chemical bonds. It is because of this potential for cancer-causing DNA damage that you wear a lead vest when you get x-rays at the dentist and you are advised to wear sunblock when you go out in the sun. One can’t avoid natural (radon, cosmic rays when you are up in an airplane) and man made (diagnostic x-rays) sources of ionizing radiation completely, but it is reasonable advice to minimize exposure when possible.
Although common sense, spending as little time on your computer as possible, and when you’re not using it, disabling the Wi-Fi connection or even turning your computer off completely, is recommended to help keep EMF pollution to a minimum. These devices emit a constant stream of EMFs when plugged in and “synced” up to a router or other wireless device.
The tricky part about measuring the radiation from a cell phone is that the emission strength varies widely over time. There will be strong bursts of varying intensity, followed by quiet periods. This makes it hard to compare "apples to apples". Also, because you are measuring up close to the source, you must use a near field meter AND you must maintain the position of the meter very precisely.
The frequency of radiofrequency electromagnetic radiation ranges from 30 kilohertz (30 kHz, or 30,000 Hz) to 300 gigahertz (300 GHz, or 300 billion Hz). Electromagnetic fields in the radiofrequency range are used for telecommunications applications, including cell phones, televisions, and radio transmissions. The human body absorbs energy from devices that emit radiofrequency electromagnetic radiation. The dose of the absorbed energy is estimated using a measure called the specific absorption rate (SAR), which is expressed in watts per kilogram of body weight.