There's actually a "Patient-contributed data" initiative being run by the standards body (HL7) that's gaining traction. In an ideal world it would allow patients to "push" their electronic records to a new practitioner, meaning that intake forms could be much simpler. In practice I think the implementation is going to start with Observations/Lab Results first though.

I hope to eventually support it with my open source personal health record (PHR) Fasten Health. IMO this would be a "killer app" for PHRs.