Have written about this bag before here. I really like it for many reasons – it is light, hardy, waterproof, fits A4, stands upright, is well designed and has a firm protective base (similar to a Converse sneaker) which you can stand on the ground without compromising the rest of the bag. It is also not pricey.
This particular one is a wonderful combination of practical khaki and pretty pink, with large zipper details. It has both shoulder and hand straps, many useful pockets, padded sides and internal pockets for all kinds of things.
This bag would be brilliant for school, university, the beach and traveling. I had my previous one a long time and it was pretty hardy. This one came from Gifts With Style. They have lightning fast international delivery.