I've recently been away from home at a training course so have been using webmail clients instead of my outlook/express/thunderbird clients. Yahoo's new webmail client is amazingly good - very slick. I gather they bought the underlying technology from oddpost.com and have been busy building it into their main offering, as someone trying to create a new consumer site its profoundly depressing as they have raised the bar quite a lot higher.
Anyway, as I was back in webmail-land I had a look in my old mail folders and re-discovered stuff from way back (2000-2002) and found some correspondence with www.isabel.org.uk when I was trying to get some support for Medys from fellow-travellers. Well Isable.org.uk is now www.isabelhealthcare.com ! and slightly slicker than it was back then. They charge a few hundred US$ to subscribe but offer free 30 day trials. I signed up and tried then out with some LCH symptoms. It did provide LCH as a differential diagnosis when I used "Professional" phrases such as "diabetes insipidus" and "otitis media" but didn't when I put in stuff in lay-terms. So - basically I think it was a success as it is a service for primarily for the professionals. I think, again, there could be some scope for providing links to their site and may well get in touch with them to see what's possible.