(Sorry about the sloppy formatting - it was my first time doing an in-post poll and I can't change it now since people have already voted.)
Without exception, every person who I have heard say "acrosst" with the T at the end has been from Utah, or was raised by people from Utah, or had strong Utah influences on their linguistic upbringing. This includes Ken Jennings, by the way, if I remember correctly (edit: apparently I don't). I can't figure this one out. It is as puzzling to me as crayon=crown was to some of you.
What is going on here? Why the final T sound? Am I the only one who has heard it pronounced that way?
Peripheral discussion: I have noticed that someone who says "acrosst" often says "drownded" (for "drowned") and "drawled" (for "drawed," which itself should be "drew"). Again, what is going on here?