If you will settle for an iPad it does offer a full size keyboard in some apps, but which ones depends upon the API chosen by the app developer. The iPhone's keyboard in landscape mode is not a four row keyboard if that is what you mean, but it is larger and to me easier to use. Don't forget there are also left and right one handed keyboards for those with agile thumbs — the kids love them.

If we knew what it was we were doing, it wouldn't be called research, would it?

— Albert Einstein