A simple command line tool to view assembly references.
Download AsmSpy as a .zip here. The .zip file contains AsmSpy.exe.
Simply run AsmSpy giving it a path to your bin directory (the folder where your project's assemblies live).
AsmSpy D:\Source\sutekishop\Suteki.Shop\Suteki.Shop\bin
It will output a list of all conflicting assembly references. That is where different assemblies in your bin folder reference different versions of the same assembly.
To see a list of all assemblies and all references, just add the 'all' flag:
AsmSpy D:\Source\sutekishop\Suteki.Shop\Suteki.Shop\bin all
To ignore system assemblies, add the 'nonsystem' flag.
The output looks something like this:
Reference: System.Runtime.Serialization
3.0.0.0 by Microsoft.ServiceModel.Samples.XmlRpc
3.0.0.0 by Microsoft.Web.Mvc
4.0.0.0 by Suteki.Shop
Reference: System.Web.Mvc
2.0.0.0 by Microsoft.Web.Mvc
3.0.0.0 by MvcContrib
3.0.0.0 by MvcContrib.FluentHtml
3.0.0.0 by Suteki.Common
2.0.0.0 by Suteki.Common
3.0.0.0 by Suteki.Shop
2.0.0.0 by Suteki.Shop
Reference: System.ServiceModel.Web
3.5.0.0 by Microsoft.Web.Mvc
Reference: System.Web.Abstractions
3.5.0.0 by Microsoft.Web.Mvc
You can see that System.Web.Mvc is referenced by 7 assemblies in my bin folder. Some reference version 2.0.0.0 and some version 3.0.0.0. I can now resolve any conflicts.