Again, thank you for the response. Sorry about if I am unable to clairify my requirement to you. My WCF webservice is running on a server where there is no dotnetnuke. It's just a server where we have all the webservices hosted. As you mentioned, I did already try getting the reference of that service to my dotnetnuke site project and even though it added the service reference correctly and created the endpoints, but it throws an error ("cannot authenticate the user") when I try to load module from dnn where I used the result from the webservice to bind to a gridview.
But it works fine when I access the WCF service from a asp.net web project client.
So, I am thinking if this might be a dnn issue/limitation which doesn't support external WCF webservice call.

Any suggestions on this? I think this is a very basic requirement which most businesses may have. So, not sure if I am missing something. If I could get a sample which shows exactly how to create a dnn module that can call a external WCF webservice that would be great. I know if I publish my WCF webservice inside desktop mosules of DNN, it will work. But my requirement is how to invoke external wcf webservice from DNN.

Again, appreciate all your help on this. Thanks, Royji