Don"t talk: your cell phone may be eavesdropping. Thanks to recent developments in "spy phone" software, a do-it-yourself spook can now wirelessly transfer a wiretapping program to any mobile phone. The programs are inexpensive, and the transfer requires no special skill. The would-be spy needs to get his hands on your phone to press keys authorizing the download, but it takes just a few minutes—about the time needed to download a ringtone. This new generation of user-friendly ipyphone software has become widely available in the last year— and it confers stunning powers. The latest programs can silently turn on handset microphones even when no call is being made, allowing a spy to listen to voices in a room halfway around the world. Targets are none the wiser: neither call logs nor phone bills show records of the secretly transmitted data. More than 200 companies sell spy-phone software online, at prices as low as $50. Vendors are loath to release sales figures. But some experts claim that a surprising number of people carry a mobile that has been compromised, usually by a spouse, lover, parent or co-worker. Many employees, experts say, hope to discover a supervisor"s dishonest dealings and tip off the top boss anonymously. Max Maiellaro, head of Agata Christie Investigation, a private-investigation firm in Milan, estimates that 3 percent of mobiles in France and Germany are tapped, and about 5 percent or so in Greece, Italy, Romania and Spain. James Atkinson, a spy-phone expert at Granite Island Group, a security consultancy in Gloucester, Massachusetts, puts the number of tapped phones in the U.S. at 3 percent. Even if these numbers are inflated, clearly many otherwise law-abiding citizens are willing to break wiretapping laws. Spyware thrives on iPhones, BlackBerrys and other smart phones because they have ample processing power. In the United States, the spread of GSM networks, which are more vulnerable than older technologies, has also enlarged the pool of potential victims. Spyware being developed for law-enforcement agencies will accompany a text message and automatically install itself in the victim"s phone when the message is opened, according to an Italian developer who declined to be identified. One worry is that the software will find its way into the hands of criminals. The current embarrassment is partly the result of decisions by Apple, Microsoft and Research In Motion(producer of the BlackBerry)to open their phones to outside application-software developers, which created the opening for spyware. Antivirus and security programs developed for computers require too much processing power, even for smart phones. Although security programs are available for phones, by and large users haven"t given the threat much thought If the spying keeps spreading, that may change soon.