If you live in California, or are interested in the geology of this state, one new application for iPhone and iPod users to try out is the GeologyCA program offered by Integrity Logic.  The application contains 19 layers of geographic data that can be overlayed in any combination.  Layers include geology from the USGS, elevation from NASA, faultlines and earthquake epicenters greater than 4.0.  The application also integrates with the GPS capabilities of the iPhone or iPod. 

• GeologyCA Information Page
• Videos demonstrating GeologyCA
• GeologyCA iTunes Page