This online tool takes XSD schema as input and generates sample XML as output - simple as that.
Should work for most basic cases.
If you want to make a sample XML file for testing from given XSD schema file, you could spend anything from a few minutes to a few hours manually analyzing and converting XSD to XML (and be bored to tears).
Or you could use this online tool and spend just a few seconds to do it automatically!!!
Check out the XSD schema visual representation tool: VisualXSD.com
Tell your friends about it!