A heterogeneous group of people from the MIT, Tufts NEMC, Childrens Hospital (Boston) has been working in a very interesting project named the Guardian Angel Personal Lifelong Active Medical Assistant.
The BMJ has an 2001 article from that group named Public standards and patients control how to keep electronic medical records accessible but private, which is freely available for download, in .pdf format, from: Public standards and patients control.
The "Guardian Angel" project has threee main areas of development: PING (Personal Internetworked Notary and Guardian), HealthConnect and W3-EMRS (World Wide Web based Electronic Medical Record System).