and think the ambiguous ending was a little pat and too cut and dryly explained.

What I want to know is, there wasn't any explanation given for how he performed the illusions, especially the apparitions.

Is there any physical way those can be performed and was it explained anywhere?

Since the orange tree trick appears (in the film) to have had a very complicated mechanical explanation, we must assume that all the other tricks were the result of careful planning and hard work and "before their time" innovations. The fact that the magician is surrounded by a legend that he may have learned mystical tricks from mysterious otherworldly strangers and that he has lived in "the Orient" is just so much second-hand window dressing designed to keep you wonderstruck all through the film and believe in the supernatural long enough for the hero to effect his very real, very carefully-planned and very practical getaway. He does everything he does in order to elope with a woman of flesh-and-blood after all, not a ghost.

Also note that the magician fires his manager and replaces him with a crew of Chinese stagehands in order to keep his methods secret, not only from the public but also from any pressure coming from the police to divulge them. He trusts the manager with his money but not with his secrets.

The film's story also exploits the myth and mystery surrounding famous stage magicians of the XIXth century whose best tricks have been kept secret for generations by the magician's oath and never publicly revealed , some of which still seem impossible today, like one magician, David Douglas Home (see: http://en.wikipedia.org/wiki/Daniel_Dunglas_Home ), who was reputed to have levitated out of a third-storey window and flown back in through another window in front of at least a hundred witnesses who never asked for their money back.

I did not find the ending ambiguous at all, what was ambiguous about it to you? They revealed that his magic was tricks not real magic. The two lovers planned the whole thing and set the prince up. They both got away scott free. What's left to be ambiguous about?

"they were not real magic", you are actually saying yourself that a successful stage trick is "false magic" but that supernatural manifestations are "real magic".

I don't really think the ending is ambiguous, it's also too predictable.

I don't quite like what the illusionist and the girl did to the prince. The prince was not a great man, but he certainly did not deserve that.

had it coming

Use of CG in the magic tricks ruined the movie because it takes you out of the movie. Plus when I saw the CG I thought the filmmakers were going to explain what Norton was using, but evidently was suppose to be "real". I can't recommend a movie that is about practical magic yet uses CG. Just defeats the whole purpose of the film.

a model head that looked like that of the little boy who walked through the theater as a ghost. this would indicate that Norton was using dummies or prosthetics as part of his ghost illusions.

I really liked the magic he used and even i doubted if it was fake or not with the ghosts. And those model heads in his house really showed theres more to it then simply amazing spiritual powers. I mostly thought that norton was setting up the prince to pay for killing her, but the ending with her being alive even surprised me.

I didn't mind that, while it was obvious the film was saying everything Eisenstein did was a trick, it was equally obvious what he did was too good to have been so. Dramatic license.

the ending was how Giamatti's character thought how the whole thing played out. That's why when we see Norton meeting Biel, it looks hazy. IIRC, he said it was possible Norton just disappeared and went to live alone somewhere in the countryside.

a doctor and chief inspector who supposedly weren't in on the "trick" examined a body with an apparent slit throat who was really still alive, and both found no pulse or other evidence indicating this woman was faking? Lame.

The family doctor was in on it, and shooed away anyone else who tried to get a close look at the body.

the doctor was in on it