Kelly's hack makes me realize that I'm doing a better job tracking my car's maintenance records than our own health history:
I started taking note of my kids' medical histories when my oldest was a wee guy, but in notebook form. I now use an Excel spreadsheet and plan to backtrack and put in all the family medical history. I'll scan in documents as I get them (such as when we change doctors), and save it all to a DVD. Now I have a simple way to check in on medical issues, both small and large — especially helpful when watching for a pattern of illness.
I hope to get my parents and my in-laws to share their medical history too, that way my kids will always have an answer to those pesky forms at doctor's offices that ask about family health history.