Mono 3.0, Ubuntu 12.10, Nginx and ServiceStack
Firstly, if you haven't read them yet, you should go through the wiki docs on getting ServiceStack running on Mono/Linux.
What ServiceStack.dlls have you copied and where did you get them from?The ServiceStack.WebHost.Endpoints.ServiceStackHttpHandlerFactory is the ASP.NET entry point and it's available in the core ServiceStack.dll binary.
If it can't find the entry point ServiceStack.dll then there must be a problem in the Mono FastCGI/ASP.NET Host finding the ServiceStack .dlls, in an ASP.NET application it should be in the /bin folder relative to where your Web.Config is. If all the files are in the right place than it might be a file permission problem.