Yes, it's our old friend "sneak peak." This one wins as the most common word choice mistake being made these days, based on a totally unscientific survey of one person who reads a lot (me). Anyway, unless you have in mind a crafty moutaintop, it's "sneak peek."
Here's one I ran across the other day: "standing on principal." The author meant "principle," I assume.
The 'pal' version refers to that chap (or chapess) you are sent to see if you have been chewing gum or, these days, assaulting a teacher with a semi-automatic weapon during math class.
It can also refer to a sum of money that is earning you interest (although not much at the moment).
Finally, another one that seems to be proliferating: "I was pouring over your manuscript..." Not unless you were watering it. Otherwise it's "poring over."