Perhaps one of the most important features of this bag is that it fits perfectly in the Disneyworld bag storage containers on the rides.  Second is that it has a decent sized water bottle holder.  The bag has a comfortable shoulder strap with headphone cord and MP3/small cell/small camera pocket on it.  I think the bag is designed to hang on your right hip with the water bottle behind you, but my Wife and I found that if you had the bag on backwards with the water bottle forward it, it fit nicely across your back.  We preferred this method.  The pack also has a hidden stabilization strap that you can clip around your waist or hips to stop the bag swinging or flying around if you need to run or your are inverted!  The main compartment is roomy enough for the usual essentials and will hold an iPad provided you do not have a monster case on the thing.  The original iPad 1 with Apple case fit perfectly.  My new iPad 3 with chunky leather case fits more snugly.  The top has what became my camera pocket, and the front has a number of flaps and pockets that I found held small things like change, pins, medications, gum, pocket maps, and so on.  My only gripe was that the main flap zip could have been wider for my hands and that although the pen pockets were great under the flap there were a few slots that did not do much for me.  I think they are designed to hold things like business cards and small notecards, but I did not find them deep enough to be all that useful.  Overall, however, this has been a superb light travel shoulder bag and I would recommend it to anyone.  While on some of the tours at Disneyworld last year a number of people were really interested in the bag.  We actually bought ours from Altrec.com because they had a better deal than Amazon at that time.  I think prices are pretty much the same now.