Jack Wolfskin Moonwalker

Nifty suspension system allows the pack to stand away from your back and lets air circulate freely. It has Z-compression straps on the sides and two mesh side pockets for water bottles, etc.

It has a zip divider that can allow one big compartment or two smaller ones. You could actually get by on an overnighter if your bag is very compressible, like a North Face Superlight. It excels, though, for day trips, especially in spring or fall where a jacket is needed early, but you want to shed it later.

It also has a mesh front pocket in front for stuff you need to get at quickly. It has a very good waistband and is an extremely comfortable day pack.