Tom Bihn Co-Pilot ($110)

Designed, as you might imagine by its name, as an airline carry-on bag, the horizontally aligned Co-Pilot has a puffier, looser feel than Tom Bihn's other Ristretto bag. It also holds a ton of gear: a roomy inner main pocket has a removable padded iPad/Netbook sleeve, but is otherwise free to use as you wish.

Three front compartments are oddly aligned, but are meant to hold gear in the two side multipockets and a water bottle/umbrella in the vertical center pocket--a small hole in the bottom is meant to help with moisture drainage. A back pouch can hold a boarding pass/magazine, but it also unzips on the bottom to become a strap for attaching to the handle of larger wheeled luggage. The bag's undoubtedly practical and spacious, but perhaps better left for frequent fliers.