I wrote about a tool I made in this blog before (see the original article here). The tool called WSDLMerge can merge WSDL documents and XSD documents that it references into a single file.
I just updated this tool. The updated source code and now also precompiled binary version is available from the project's site.
I ran into some problems with some WSDL files, which made me update the tool. Some people also wanted a binary version instead of just source, so that is now also uploaded.
I had a WSDL file that referenced different XSD files, but with the same targetNamespace. This made WSDLMerge ignore the second import.
Also, the include statements are now getting parsed as part of the XSD files. The included schema is inlined into the schema that invokes the include.