Piano Lessons Unlimited
Piano Lessons Unlimited produces an interesting piano course that uses a rhythmic approach to playing, as opposed to the traditional, melody-accompaniment approach. In other words, he teaches you to play accompaniment patterns with both hands, while the melody is supplied from another source (some other voice or instrument).
This approach is not suitable for solo piano playing, but is indispensable for learning how to accompany someone else. I found the course to be highly useful to give me ideas on my own arrangements. The course does not teach you how to read music, because the approach of pattern playing does not require you to know how to read music. Although this course can be used without additional instruction, I would suggest using it in addition to traditional education, not in place of it.
David Sprunger (the author) has improved and expanded this project since I originally purchased it from him, and I am encouraged to think of what he might come up with next.