IPrototype p =  new prototype.PrototypeClient();

string uri = GetMeMyURI();
IPrototype p =  new prototype.PrototypeClient(new URI(uri));

BasicHttpBinding binding = new BasicHttpBinding();
EndpointAddress address = new EndpointAddress(GetMeMyURI());
PrototypeClient yourProxy = new PrototypeClient(binding, address);

PrototypeClient yourProxy = new PrototypeClient();
yourProxy.Endpoint.Address = new EndpointAddress(GetMeMyURI(), null);