Peak: the summit; highest point.
Peek: to sneak a glance.
Pique: to wound, to excite, to provoke to action.
THEREFORE, YOU DO NOT EVER
Take a "sneak peak." I really don't care if you like the symmetry. You can't spell and you just lost some of my respect.
Have your interest "peeked" or "peaked."
I can't say that I've seen many misuses of "pique," because people just seem to be entirely unaware of its existence. The smell of your favorite food piques your interest, people. You climb to the peak of a mountain, or reach the peak of activity. You take a sneak peek, for God's sake.