Right. That would be great, and actually, that's what the commercial services do.
With NWS it goes something like this: Say the user has a lat/long. You fire off an http request for a document that tells you what "quadrant" you are in and the URL for it. You then fire off a request for the quadrant document, that lists the products that are available (and their associated URLs). You then fire another request for the actual product for that quadrant . . .
This is not a real example, but this is basically how it works. Even when you can construct a single URL with the info you need, you still need to make multiple requests to have enough information to build the URL (if that makes sense).
> You can make multiple requests over a single connection.
You mean with some kind of http keep-alive thing? I'm not sure I can do that in these circumstance (with cURL).
(edits for grammar, minor issues of clarity)