I just bought the Osprey Manta 30...I think you could easily fit a smaller (i.e. 13" Macbook or similar) into the larger pocket, still leaving room for your other items. I wouldn't hesitate to use it as a daily pack for a school or work commute.
I picked this up for an overflow pack. It's black cuben fiber. gonna put a case of beer in it this weekend and test it out on a 4-day adventure. let ya know...
I'm curious to know how the, um, beerpacking went.
+1 on Sanuks. While riding they are strapped to the top of my Viscacha seat bag. Of course, I have only been on one trip so far, so this is all highly subject to change.