I have been using TrueCrypt (freeware) and RoboForm (not freeware, but worth it… there are freeware alternatives) on my PCs and flash drives for quite a while. They both perform very well, and they compliment each other’s capabilities very well.

Whether to encrypt what data is a choice that is up to you, but I do know that many hospitals do not go rummaging through your flash drive in a medical emergency because 1) their IT policy is not to plug in unknown data sources to their network, 2) they do not have the time, and/or 3) they don’t know what they’re doing with a computer. (As a former IT support provider for hospitals and medical records, #3 is the case far more than I am comfortable with seeing as how these people are responsible for my health in many ways.)

For medical information availability, it may be much more prudent to carry a dedicated method such as a medical ID tag, card, or something of that sort. There are companies such as MedicAlert that can provide full information, including past medical records, to hospital staff when they need it without you having to be conscious. The benefits and comparisons of these dedicated methods are beyond the scope of this thread, however.