Take a look at ILMerge:
http://www.microsoft.com/downloads/en/details.aspx?familyid=22914587-b4ad-4eae-87cf-b14ae6a939b0&displaylang=en
http://www.codeproject.com/KB/dotnet/mergingassemblies.aspx
With ILMerge you can merge a bunch of assemblies by running the command like:
ilmerge /out:MergedAssembly.dll ProjectAssembly1.dll ProjectAssembly2.dll ProjectAssembly3.dll
This will merge 3 assemblies into a single one.