Taking a business trip to a frigid city? Fighting humidity on a weekend vacation? Or do you simply need to a hair pick-me-up during your extra-long workday? These travel-size must-haves are essential products to keep nearby for your face, hair and nails. Most are no-brainers; others are the stuff you find yourself tapping a friend for. Stash the following at your office or inside your carry-all bag. Trust me, you’ll thank us later.