If you want to use CardSpace from a WCF client without hard-coding config or using an App.config file then try using the MetadataResolver class. Here is some code that works with .NET Framework 3.0 Beta 2 ("WinFX"):

I've been meaning to get a MetadataResolver example working for a while and I was finally able to spend some time today with it. Not too difficult although it's due to change a little bit with the June CTP. The revocation check was necessary to get around my certificate CRL being unavailable.

using System;
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.ServiceModel.Description;
using System.IdentityModel.Selectors;

namespace HelloClient
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                Uri mexUri = new Uri("http://localhost:4123/helloService/mex");
                EndpointAddress mexEndpointAddress = new EndpointAddress(mexUri);
                ServiceEndpointCollection endpoints = MetadataResolver.Resolve(mexEndpointAddress);

                ContractDescription contract = ContractDescription.GetContract(typeof(HelloService.IHello));

                foreach (ServiceEndpoint endpoint in endpoints)
                {
                    if (endpoint.Contract.Namespace.Equals(contract.Namespace) && endpoint.Contract.Name.Equals(contract.Name))
                    {
                        ChannelFactory<HelloService.IHello> cf =
                            new ChannelFactory<HelloService.IHello>(endpoint.Binding, endpoint.Address);

                        InfoCardClientCredentials credentials = new InfoCardClientCredentials();
                        credentials.ServiceCertificate.Authentication.RevocationMode = System.Security.Cryptography.X509Certificates.X509RevocationMode.NoCheck;             
                        cf.Endpoint.Behaviors.Add(credentials);
                       
                        HelloService.IHello chn = cf.CreateChannel();                        
                        Console.WriteLine(chn.Say());
                        cf.Close();

                    }
                }
            }
            catch (UserCancellationException)
            {
                Console.WriteLine("User cancelled");
            }
            catch (UntrustedRecipientException)
            {
                Console.WriteLine("User does not trust the recipient");
            }
            catch (ServiceNotStartedException)
            {
                Console.WriteLine("CardSpace service not started");
            }
            catch (InfoCardException ice)
            {
                Console.WriteLine("Generic CardSpace exception :" + ice.Message);
            }
            catch (Exception e)
            {
                Console.WriteLine("Other exceptions :" + e.Message);
            }
            finally
            {
                Console.WriteLine("Press any key to finish");
                Console.ReadKey();

            }

        }
    }
}