The guy at WellConsdered.be made a WebService package for AS3. I've only done testing with it, but it appeared in a book and it seems to work fine.

Here is a link to the site where you can get the code:
WellConsidered.be

This is an example code. Just put this on the main timeline frame one:

Code:
import be.wellconsidered.services.WebService;
import be.wellconsidered.services.Operation;
import be.wellconsidered.services.events.OperationEvent;

var ws = new WebService("http://www.webservicex.net/WeatherForecast.asmx?wsdl");

var op:Operation = new Operation(ws);

op.addEventListener (OperationEvent.COMPLETE, onResult);
op.addEventListener (OperationEvent.FAILED, onFault);

op.GetWeatherByPlaceName ("new york");

function onResult (e:OperationEvent):void {
	for (var prop in e.data){
		trace (e.data[prop]);
	}
}
function onFault (e:OperationEvent):void {
	trace (e.data);
}