A video from Rory at WebMapSolutions gives a running example of using ArcGIS mobile in a disconnected environment.  From Rory – You might be wondering how you access GIS layers when your mobile has no Wi-FI access. Well wait no more, the solution is at hand. The demo below shows ArcGIS being used offline. Before you open source folk get upset, this solution could also be applied to a Geoserver/Openlayers/OpenScales solution. The app shows storage of base map tiles and a shapefile on the actual mobile device. In offline mode, we show loading this data. Very cool