Personal locator services based on the GPS-enabled mobile phone will grow from their current small user-base of just 500,000 in North America to a total of more than 20 mln subscribers in 2011, according to ABI Research. First launched in South Korea and Japan, personal locator services are not well-entrenched yet even there, but on a conservative forecast could reach 34 mln Asia-Pacific subscribers by 2011. They are expected to go on offer in Western Europe in 2007.