I'll admit it... I did it once, before my 3-week post-college-graduation backpacking trip to Europe. I took one of those blue/pink striped blankets from BA Y (I can't believe they still use those). But man, was it worth it... small, compact and disposable. I used it as the first layer of my bedding. Especially came in handy as I slept at The Tent in Munich, on the front steps of the Barcelona Central Station, on the platform at the Pamplona train station, and on the grassy area by the Eiffel Tower.

But what is with people who stuff the blankets into their carryons? I've even seen someone take one, then use another for the flight!