Gas-powered cell phones aren't just a lot of hot air, according to Motorola. Motorola researchers announced on Tuesday that they have successfully demonstrated a methanol gas-powered fuel cell, which can provide enough juice between chargings for a month of cell phone calls. The fuel cell is essentially a miniature electrochemical plant that fits into a belt holster. Inside the cell, methanol is stored in an area the size of a ballpoint pen's ink holder. A chemical reaction releases oxygen, heat and electricity. The electricity then either powers the phone directly or, in the case of Motorola's product, charges another battery that can then power the phone. The trick, says Motorola, isn't creating small devices to do each step, such as guiding the methanol's path or ensuring the electricity is sent to the phone. Instead, Motorola has created one device to do everything. On Tuesday, the company said it has managed to lump together each of the working parts into a device that measures about 2 inches wide, 4 inches long and about a half-inch thick. For a cell phone owner, that amounts to carrying a device a little bit longer and wider than an ordinary cell phone battery. Motorola isn't alone in its research. The consumer-electronics industry has been hunting for a way to replace nickel cadmium batteries that power most portable electronic devices in the world today. Consumer-electronic giants NEC and Sony are developing similar types of batteries. Smaller research outfits including Mechanical Technology and Manhattan Scientifics have recently announced similar breakthroughs. "We are at the point where the technology has been proven," said Greg Dolan, vice president for communications and policy at The Methanol Institute. "Now the challenge is to prepare the fuel cells for mass production." That could take anywhere between two and four years, most analysts agree. For example, Allied Business Intelligence says there could be 200 million of these batteries powering cell phones, personal digital assistants and laptops by 2010. Motorola isn't predicting when it will sell the batteries on a wide scale. NEC expects its product to be in production between 2003 and 2005. Sony has yet to say when it expects to commercialise its technology. See the Mobile Technology News Section for full coverage. Have your say instantly, and see what others have said. Click on the TalkBack button and go to the Telecoms forum. Let the editors know what you think in the Mailroom. And read other letters.