I had a traditional diaper bag when C was born that was just ok- not terrible, but not the easiest to use or pack and not super stylish (skip hop studio. Meh.) I've been just using a regular messenger bag for a while since c is a little older and I don't need to bring all the things everywhere.

Now with a second coming, I think I want a back pack so I can have both hands free, plus it's better for my not great back. So recommendations for a back pack that you like as a diaper bag? I'd like two outside pockets for cups/bottles, and some inner compartments or pockets but nothing crazy since I usually just jam things in and organize with ziploc bags as needed. Comfortable and light weight are musts, and preferably something that's not terribly ugly.