I've noticed a lot of posts about piano lessons and thought it would be helpful to let everyone know about a great option that I've been using with my 5-year-old son. The lessons are through http://www.peerypiano.com and it's actually a conservatory-level online piano instruction. The teacher, Christie Skousen, studied with Leon Fleisher at the Peabody Conservatory. If you don't know who that is, just know he's a leading performer and teacher in the U.S. The curriculum used on PeeryPiano is also used at the San Fransisco Conservatory for their young students.
I had concerns at first with taking piano online, but my fears quickly vanished. You can submit videos of your playing and Christie personally responds with a video response. I actually like it better than regular lessons because I can have my son watch the video instruction whenever he wants rather than just at a lesson. He can also progress at his own pace which is sometimes faster and sometimes slower than the typical week-long cycle.
I hope this is helpful for those looking for piano lessons. Let me know if you have any questions about my experience with it. I'd be happy to tell you what I know.
Sam