http://massivehealth.com/ - stealth startup cofounded by Aza Raskin (former creative lead at Firefox).

https://cakehealth.com/ - mint.com for healthcare.

http://carelogger.com - diabetes logbook (my site)

http://patientslikeme.com - illness community

These events are a great place to find the interesting new people and ideas http://www.health2con.com/

http://www.halomonitoring.com - senior citizen health monitoring and automatic fall detection

http://dsharpdiabetes.com - Mobile Diabetes Management platform using JQuery Mobile.

http://www.diagnosia.com/en/ - European source for medical drug information

http://www.wakemate.com/ - analyze sleep patterns.

www.23andme.com - DNA profiler for ancestry and common gene related diseases/conditions