Kimberly Gerhart is compiling spreadsheets and tending to clients via email, but this is no ordinary work trip. Just in front of her sits a margarita; a little farther away, the Pacific Ocean shimmers. Gerhart's employer, back in Indianapolis, has footed the bill for her "work" abroad trip in Malibu — not that there's a client, prospect or branch office there.

By now, much of the professional world has dispensed with the 9-to-5 workday, and while death by overwork is rife in Japan and China, the always-on culture has spread around the world. Our vacation policies have not kept pace.