Help me pick a book cover for The Five-Day Turnaround!

My upcoming book, The Five-Day Turnaround, is focused on helping leaders at established businesses act more entrepreneurial, allowing them to unlock faster growth and achieve greater success. I'm looking for a book cover that will grab someone's attention, whether it's on a shelf in a bookstore or (more likely) on Amazon.com. Thanks for helping!

(you can click on the images to see a larger image)