VisStudio AddIn to automatically save files
I have implemented similar behavior in addins for Visual Studio 2010 and
Visual Studio 11 (Beta) VS2012.
When Visual Studio loses focus, all modified documents are saved.
Extract the appropriate zip file to your AddIns directory, and use Tools->Add-In Manager to enable. There is some output in the Output window when the add-in is loaded, and when files are saved.
Please contact me if you have any problems (or suggestions!).