My English Cocker, Dusty, is the smartest dog I have ever known.  She came from the Nite Winds Kennels and I have found it so easy to train her to do just about anything.  She learned to ring the bell on the back door to ask to go out in ten minutes.  (Now she rings it, goes out for 10 seconds, and comes back in for a treat.)  We tried to keep her in a pen, but she learned to climb over.