ArcGIS for iOS. The initial version of the app lets users find and share maps from ArcGIS Servers, and offers tools for searching, identifying, measuring, and querying those databases. Future versions of the app should enable users to collect and update GIS features and attributes, as well as perform GIS analysis by accessing geoprocessing tasks on the server. A beta of the ArcGIS API for iOS is also currently available, with release anticipated in the third-quarter of 2010.
There are a number of geology-related databases highlighted in this initial release as Featured Content, such as North American Geology and Kentucky Geology. Other databases of interest, which currently show up under Popular Content include various Bing layers (including maps, aerial, hybrid, and road), OpenStreetMap, USA Topo Maps, and Terrain. And, of course, you can point the app at your own favorite ArcGIS Server data sources.
ArcGIS for iOS does require an internet connection to access data on ArcGIS Servers. So, if you're going to be in areas without cellular or Wi-Fi data coverage, then Integrity Logic's geology and geography iPhone apps, which include a wealth of off-line data, are worth a look. They were quite useful during a recent two-week geology field trip to the southwestern US; more on that in a future post.