Very Powerful Internal Animal Forms

I really, really like this video showing the exercises of Xinyiliuhe, more on the style in a moment.
First of all, consider the variety of technique and the amount of exercise this guy gets done in an extremely small space, no larger than an elevator. Watch as he first goes through the particular animal form with relaxed attitude. Gradually he builds until you can clearly see the martial intent. The spurring of the Rooster, the siezing of the Eagle, the knock-down power of the bear, the defensive covering from blows to the head as the Tiger washes his face. Nice elbow striking also.
Now for the style itself:
The best information I found was here on Jerek Szymanski's "China From Inside". Jerek is a very active journalist and historian living and Training in China, and has some of the best reporting on the lineage of Chinese martial arts.
"As stated in his article, Xinyiliuhe is a Moslem (his spelling) martial art meaning "Fist of Mind, Intention and Six Harmonies". From Jerek's article:
The art of Xinyi Liuhe Quan was passed secretly among Chinese Moslems and has been known as "the most cruel style among Chinese martial arts"

-- As I said above, see how little room you need to do a complete martial arts workout? I can run an hour of Tai Chi Chuan, intense Bagua and a cool-down with Xingyi in less than an eight-by-twelve area (although I prefer outdoors).

Oh, and by the way, I shamelessly ripped this cool video off from The Emptyflower Forum, a source for lots of Chinese internal arts stuff.