cURL (groks URL) can be used as a SOAP client to send XML SOAP requests to web services. But the problems that I was facing in sending the data directly with the -d switch of curl is that DOS command shell would greet me with an error message:

< was unexpected at this time.

But there is a great way to send data in the POST requests by using the -d switch with the @ symbol. For example to send the xml data in the xmlfilewithdata.xml in the POST request to http://www.somesite.com/thewebservice you could use the following command:
curl -d @xmlfilewithdata.xml http://www.somesite.com/thewebservice

Off go all the errors and there it is …. your SOAP client – cURL!