Study - Cell Phones In Hospitals Can Be Dangerous
 

A new Dutch study on mobile phone signals finds that using a cell phone in restricted areas, such as hospitals, can be dangerous. In the study, published Wednesday in the online journal Critical Care, researchers measured the impact of electromagnetic interference (EMI) from cell phone use on hospital equipment such as ventilators and pacemakers.

Yeah I heard that Cingular phones are perfectly safe because their jitter and dropped calls prevent customers from actually using their service. :D