"Australia has one of the highest rates of mobile phone ownership in the developed world among children," the Sydney Morning Herald reports, so its Communications and Media Authority issued some tips to help keep kids' cellphone costs under control. Developed with the help of London-based Childnet International, suggestions include considering pre-paid phone services with built-in limits, using providers that track use between billing periods, using services that block extras like Internet access. For more suggestions, see "Ask these questions first" at the bottom of the Morning Herald article. The paper cites one expert as saying this can be a good opportunity for early family discussions about budgeting time and money. Children as young as five have mobiles in Australia.