TurboSite ($499) is probably the best app out there for collecting onsite data. It runs on iPads only for now, but IMSI/Design has added the ability to plug the collected data right into AutoCAD and Revit. Here's how one press release words it:
With the launch of TurboSite Plug-In For Revit, all Revit users on a project can, for the first time, view correctly geolocated video, photo, markup, and text documentation directly within Revit. TurboSite Plug-In For Revit is free and available now through the Autodesk Exchange for Revit.
The same is available free for AutoCAD, and here's a pic of the plug-in at work: