Hi,
Using the web service interface, you can send a file as an attachment to the Generator without providing the URL. This works well for MS Office documents, pictures or text files. I haven't experienced with html files, so I don't know what happens with links or embedded content such as pictures included in the HTML page. I guess linked pictures must be accessible from the Adobe PDF Generator server.
You can also use the watchfolder interfaces: simply copy your file to the appropriate folder and it will be converted.