This Blog talks about it.
And these people are interested
Not very useful
I imagine you could do much of this via XML Import, submitting the URL, but with XML returned. As long as it only requires an HTTP request with an developer key, FileMaker can natively submit a GET (not POST) request, and import the result directly. You would however need a simple XSL stylesheet to convert the xml returned to FileMaker XMLRESULT syntax.
The advantage of XML Import is that it does not require a Web Viewer, or any element on the interface. Nor would it require you to trap for whether the data had arrived (as I believe you must do with a Web Viewer, but is easy to do); XML Imports know when they're done.
The question is which is faster and/or easier, how much speed even matters. I imagine the Custom Function he mentioned is capable of getting the correct data from the return (since he's using it). If so, then likely the Web Viewer, with JSON return is less work. I imagine the XML Import would be a little faster in mass operation.
David and Fenton,
Thanks so much - this was exactly what I was looking for. I started reading the first link in Davids post and see that a custome function is required, however it my version - FileMaker Pro 11 dosent seem to support custom functions - I think you need the advanced version. At least I don't have the menu option onder File / Manage. I'll keep reading and see what I can find out.