Nana said:ba gua kan, a kind of extraordinarily violent tai chi.
Yeah, Bag Gua Zhang is another cool internal MA... very fast and consists of coiling/uncoiing techniques in order to generate power. It was widely used by bodyguards in China a couple of hundred years back.
If you want to learn about a SERIOUSLY kickass internal MA then take a look at this... Baji Quan (or The Bodyguard Art), when combined with the art Piqua (the softer aspects) that it is regularly taught with the old saying goes...
"When pigua is added to baji, gods and demons will all be terrified" and "When baji is added to pigua , heros will sigh knowing they is no match against it."
It was widely used by the hard-nut imperial bodyguardes in the last few centuries and revolves around short, powerful strikes using elbows, knees etc. It was one of the most feared arts there was http://www.geocities.com/Tokyo/Dojo/2457/baji.html
Another one worth looking up is Xing-Yi which is another internal art where one practitioner once famously won a full-contact MA tournament using just one type of punch http://www.shenwu.com/hsingi.htm
More about Tai-CHi http://www.shenwu.com/taichi.htm
More about Bagua http://www.shenwu.com/bagua.htm
Heh that's what I love about MA... there's so many different styles and things to learn about it's fascinating. others will no doubt be bored stiff.