SymCAT is another piece of software that appears* to use Bayesian methods to suggest possible diagnoses (it has a mobile app for Android).
*they don't actually mention "Bayes" (or give much detail at all) in any of the descriptions I can find, but they talk about machine learning and "frequency and likelihood", as well as giving giving the probability of each possible diagnosis given the symptoms.
Bayes at the Bedside and Rx-Bayes come with databases of likelihood ratios and help doctors estimate probabilities from their phones. I met somebody at Singularity Summit 2011 who used one of them, but I can't remember which.