(Photo: Wikimedia Commons via CC Attribution)
Downy Wrinkle Releaser
This stuff is a must when you're packing cotton, silk, linen, or other wrinkle-prone fabrics—especially when traveling to an iron-free zone, like a cruise-ship cabin. (For fire-safety reasons, irons are banned in most ship cabins.) I've successfully used Downy Wrinkle Releaser on many a trip, so I can vouch that it works like a charm. I've found that severely wrinkled garments that require a good deal of spray can get a little damp, so sometimes it's best to spray-and-tug your clothes the day before you wear them, hanging them to dry. Cost: $4.75 for a pack of two travel-size bottles on Soap.com.