Visual Studio creates an AssemblyInfo.cs file for each project in a solution in a 'Properties' folder. Thing is that, more often than not, I'm more interesting in an application's version than the individual assembly's version, and the solution is the application. So I find that each time I create solution with multiple projects (assemblies) I add a 'Common' project that has an AssemblyInfo.cs file to be used by all other projects. That way all assemblies have the same version information.
To do this delete the AssemblyInfo.cs file in each project and then 'Add Existing item' browse to the common AssemblyInfo.cs and add as link. This way all projects share the same AssemblyInfo.cs file. Unfortunately Visual Studio does not allow adding any items to the 'Properties' folder.
Good way to go even if the AssemblyInfo.cs file is manually updated or created/updated automatically.