I found the technique intriguing, but troubling in implementation. The problem I had in particular the way it completely obscured the content underneath each field (there was help for every field). I would have liked if it had only covered up the fields below the active field with a mostly opaque help box. But, as it was it would cover a field I just entered.

Then, there was the auto tabbing. Stop that. I accidentally tabbed through the month field, and then couldn’t tab BACK into the month field because of broken logic in the “day” field.