My wife asked for a Nativity scene for our front yard. Rather than carving it out of wood, I gave foam a try. I've seen this product used many times online and figured it would be an inexpensive experiment. I learned a few things, and the wifey appreciated the result. Win-Win in my book.
The cool thing is foam carves so effortlessly that, I imagine, you could easily carve it with a trim router.