Mostly used by girls who ignore their pretty male companions when they are talking to them. The phrase is used when you clue in that that person is talking and you are at loss for what they are saying.
Jon: Hey Sunshine. My computer game... blah, blah, blah, blah...
Jon: What do you think??
Sunshine: What in the whohanow are you talking about??
Sunshine: What in the whohanow made you think I was even listening??
Whohanow, also spelled "who-ha-now" was derived from "who in the what now." although many have debated as to whether the word truly exists, one finds it hard to converse with certain people without using this witty term.
ERICA!!! CRIPES, what in the whohanow do you think you're doing?! STOP RUBBING YOURSELF WITH THOSE SOCKS!!!
Derived from the statement "who in the what now" (compliments of Jasper from The Simpsons) it is a term used following "what in the..." statements to accent a person's perplexed nature.
Funk: "The jazz!"
Me: "what in the whohanow are you talkin about, Funker?"
it's an actual word I swear... I heard it once while hanging around this guy with the hair and the whatnot's
Jon, what in whohanow are you doing??