ARUP laboratories a service from the University of Utah have made their excellent reference available for the PDA.
The reference is very useful at the bedside as it is centered around diseases rather than lab tests which is very practical when it comes to patients encounter.
The Avantgo channel loads fairly quickly with simple interface, feedback link, frequent updates and the Avantgo software is compatible even with Blackberry.
Best of all, the service is absolutely Free with no need for registration even.
For pediatricians this reference may not seem very attractive first because of the general medical nature of it but in fact browsing deeply into the contents reveals a good amount of pediatric content.
The Arupconsult is also categorized in the Mobile Sites category.