I have a GR8X bag backpack that is great, BUT I've just bought a Crumpler bag about 2 weeks and it is BRILLIANT!!

It's actually a Crumpler camera bag!!! it has all these dividers in it meant for camera stuff, but it is PERFECT as a baby bag. one section for baby food, one for sippy cups, one for medicines, one for wipes, etc. plus side pockets for my phone and a zip up section for stuff you don't want little fingers to get into.

I'd totally recomend checking out crumpler!

they have heaps of different types of bags and all are really well made and tough and I wish i'd thought of it sooner!!