Walls and Ceilings - step ceiling question

Here's the story, my mother is on a tight budget and wants some flare added to her new home. I'm already adding a couple walls and taking some out, but in the kitchen I wanted to add a couple steps in the ceiling for depth. I want to do it the tradidtional way which I have done many times, but she is one of those women that watches HGTV and trading spaces too much and wants me to do it with foam?? Anybody ever seen this or done this? What kind of foam, how did you attach and blend it into the existing walls ceiling so it looked like it was alwyas there, and what has to be done in order to paint this foam? Hopefully I'll get zero responses cause she has all these great cheap "foam ideas" for around the house...wow, they oughta ban them programs!! Thanks if anybody has any info. Josh

We see the end of a Trading Spaces or a home improvement/design show and through the eyes of the camera lens, all looks great. Unfortunately, the real world isn't like that. Professional looking, lasting results can only be obtained by using real building materials such as framing and wallboard. At more than a passing glance, foam on the wall or ceiling will look always look just like foam.

Well that's kinda what I was thinking, but then again there is so much going on with homes nowdays, it's impossible to keep up on every facet. I try to keep an open mind to new ideas because that's what I have to do to stay competitive, but on the other side on the coin I'm also hard to sway from what works. It's not like we're talking about alot of money for materials to begin with for this project and since she's my mother I would'nt feel right charging her for labor, so she's getting a great deal here from the get go, but these frickin shows literally give me a headache when it comes to giving people what they want. "Well they did this," or "they did that" with $10...you get the idea:D
She's just gonna have to live with the fact of spending a little more for a permanent solution since I do not like the idea of doing anything twice.

What would be the advantage of foam? Is there something funky she wants done?