REST service returning "useful" information for demos

I am looking for a REST service that I could use in demo code. I'd like the service:

• To take at least one parameter (as a request parameter, or XML PO开发者_StackOverflowSTed as the body of the HTTP request).
• To return the result as XML (not JSON).
• To be accessible anonymously (I'll call the service in sample code, so I don't want to put my key in the code, or request users to get a key).

When the Twitter API supported XML (not just JSON), I was typically using their search API. But really anything mainstream enough, easy enough to understand will do (information about zip code, weather for a city…).

If you are using .Net, why don't you just create a tiny MVC application that has a controller that exposes a method that returns some sort of formatted XML? That way you can run the whole thing locally.

EDIT:

You know, I think you can use Google Maps API without a key. I created a test project a couple of days ago. Here is a .Net code snippet (only included so that you can see how I am calling the service):

private static string GetString(Uri requestUri)
{
   var output = string.Empty;

   var response = WebRequest.Create(requestUri).GetResponse();
   var stream = response.GetResponseStream();
   if (stream != null)
   {
      using (var reader = new StreamReader(stream))
      {
         output = reader.ReadToEnd();
         reader.Close();
      }
   }
   response.Close();
   return output;
}

I pass in a uri with a url:

https://maps.googleapis.com/maps/api/directions/xml?mode=walking&origin={0},{1}&destination={2},{3}&sensor=false

Where {0},{1} are the first lat/long, and {2},{3} are the second. I am not attaching a key to this and it worked for testing. My method returns a string that later I handle like so:

var response = XDocument.Parse(GetString(request));

which gives me back xml. Again, I still recommend just creating your own web app and then deploying it somewhere publicly accessible (either in a LAN or on the web), but if you just need a web service to return XML you can use that.

The Yahoo! Weather API can be used for this. It takes a location as a request parameter and returns the weather forecast for that location as XML. It also returns weather information as HTML, which you could display as-is to the user. You can see an example of this below. Also make sure that you respect the term of use described at the bottom of the Weather API documentation page.