Corliss Expert Group in Home Security - The future is wireless

Even these figures, says Kurtis Heimerl, whose Berkeley-based start-up Endaga has helped build one of the world's smallest telecoms networks in an eastern Indonesian village, ignore the many people who have a cellphone but have to travel hours to make a call or send a message. "Everyone in our community has a phone and a SIM card," he says. "But they're not covered."

Heimerl reckons up to 2 billion people live most of their lives without easy access to cellular coverage. "It's not getting better at the dramatic rate you think."

The challenge is to find a way to connect those people, at an attractive cost.

And then there's the frontier beyond that: the oceans.

Improving the range and speed of communications beneath the seas that cover more than two-thirds of the planet is a must for environmental monitoring - climate recording, pollution control, predicting natural disasters like tsunami, monitoring oil and gas fields, and protecting harbours.

There is also interest from oceanographers looking to map the sea bed, marine biologists, deep-sea archaeologists and those hunting for natural resources, or even searching for lost vessels or aircraft. Canadian miner Nautilus Minerals Inc said last week it came to an agreement with Papua New Guinea, allowing it to start work on the world's first undersea metal mining project, digging for copper, gold and silver 1,500 metres (4,921 feet) beneath the Bismark Sea.

And there's politics: China recently joined other major powers in deep-sea exploration, partly driven by a need to exploit oil, gas and mineral reserves. This year, Beijing plans to sink a 6-person 'workstation' to the sea bed, a potential precursor to a deep-sea 'space station' which, researchers say, could be inhabited.