I use this bag as my purse.  It goes everywhere with me.  It fits my iPad with a few books (or a netbook...) with room to spare.  The only thing I would change is the strap - it needs to be able to go shorter so I can snug the bag up against me when I want to run and it needs to quit sliding. the square rings in the strap are in the perfect spot for me to clip my keys onto it.  I keep papers that I need repeatedly in the pocket against the back so they don't get mussed.  Love this bag.  I'm plotting what color will be next.

Almost 2 years later...Still loving it.  My next one will be darker so that it doesn't show scuff marks as much, as this bag gets shoved in my scooter seat, through airport security, under the desk, etc.  NOTHING has broken.  Nothing is frayed.  The elastic on the water bottle pocket is still elastic.  It has been abused, and takes it rather well.  To give you an idea of the abuse that I put it through, it currently contains an iPad, a Kindle, a can of soda, a bottle of water, a pouch with bandages & various meds, a bag of jerky, a bag of bagel chips, 4 different travel size lotion bottles/jars, 12 pens/pencils, a sewing tape measure, a handkerchief, packets of soy sauce, a small packet of wipes, earphones, 3 chargers, sunglasses, a small pocket notebook, and an assortments of small papers I've picked up.  It was shoved into the seat of my scooter on the way to work, then under the desk.  It will probably ride home on my back once I stop by the store as there won't be room in the seat for it anymore.  LOVE THIS BAG!