As the UN recommend a boost to HIV testing and counseling one company, Voxiva, is already using mobile technology to help manage the disease in Rwanda
http://www.wirelesshealthcare.co.uk/wh/news/wk22-07-0002.htm
Also links from Mobile solutions in health care from Med-e-Tel 2007
http://www.medetel.lu/index.php?rub=educational_program&page=program