+1 for the Kelty MAP 3500, I own 3 and its a good pack. The Kelty Redwing is also good, I own several of an earlier variant with an integrated rain cover that comes in handy. Kelty makes pretty good daypacks for the masses, affordable with decent zippers and access and good suspension if your preparations get a little heavy. The Kelty MAP 3500 is great for that, but if you find you have a little less than just about any other quality day pack will do.