A small but significant barrier to the adoption of fuel cell-powered mobile phones and laptops was removed this week after the US Department of Transportation ruled that it will allow passengers to carry approved fuel cells while flying.

According to reports at CNet's Green Tech Blog, the department has decided that passengers will be allowed to carry approved methanol fuel cells and up to two spare fuel cell cartridges in their carry-on luggage.

Fuel cell-powered phones are not currently on the market, but a number of mobile phone companies including Motorola and Samsung are working on versions of the technology, with experts predicting the first models could arrive as early as next year.

Advocates of the technology claim they offer a more energy-efficient means of running personal electronic devices, such as mobiles, MP3 players and laptops, and also remove the need to charge up batteries as when a fuel cell runs out users simply replace it with a new cartridge.

The decision brings the US into line with Canada, China, Japan and the UK, all of which have already granted approval to letting passengers carry fuel cells during flights.