If you're heading out for a week or two or just know how to pack light, a carry on backpack is all you need. And if you choose a carry on with a removable day pack, you can carry them both on and have almost as much storage as a full sized backpack and travel successfully for months. Some carry on backpacks don't include day packs and may not be enough for longer trips. Either way, you'll find the best brand name carry on backpacks here including High Sierra, Mountainsmith, Lowe Alpine and Caribee Truth is, a carry on sized backpack is more than enough for most trips. So pack light and stay mobile!