I agree that the crate training is the easiest way to go. Some dogs continue to view the crate as a home...others could care less once potty training is finished. Our Havanese doesn't like or use the crate now, but it was a reasonable and fast way to potty train.

After the first night of hearing the little cries, we carried the crate (with puppy inside) into our bedroom so he slept next to our bed, in his crate. In the morning, we'd carry the crate (puppy still inside) into the kitchen, then scoop puppy up and carry him outside. After he did his thing, we'd bring him inside for play time, breakfast and then a nap in the crate (which stayed in the kitchen til night). When he woke we'd carry him outside and repeat the process. Tedious but it worked!

There's a whole other puppy training method using a Purina product that is essentially 'doggie litter'....but that's another story.