From what I can tell, hot yoga is the same thing as normal yoga only you do it in a sauna and they make you hold the poses for what seems like 20 minutes. My ass has never hurt so bad in my life {nor have I ever been so sweaty}. I must have been doing the poses wrong when I did my at-home yoga dvd.
My instructor kept referring to herself as a "yogi," which everyone but me seemed to think was perfectly normal. I, however, kept snickering like an immature little boy at every yogi mention. And yes, little boys do snicker.