We are living in an era where the general population barely reads books. We would be lucky if the next generation even knew what a book was, but technology replaced them, making it a lot easier to. You can have a tablet that could have about a thousand books, easily to fit into your bag.
However, for all the old fashioned people like me, who still think books are cool, you would have to get yourself a book bag. Book bags are bags uses to carry your books; you would get them at most book stores when you buy more books than you can carry. Currently, books are going out of date, but the bags are still pretty fashionable creating the impression you have been reading.
How easy is it to get your hands on one
You can get a book bag at a lot of stores that sell back packs; you can even get them online. There are a ton of places if you know where to look. Locally, people have even started making improvements on them, from designing to making them fancy by adding color and other material.
The largest place for the best variety would be to try your luck online, Google it.
Can I use it for anything else?
Most people I know using these bags, carry books to college, along with other stationery. They can even be used if you are heading camping or travelling to carry a few other things. Over all though, make sure the one you pick is ideal for whatever its primary purpose. If it were up to me though, I would strongly recommend using a book bag to get a few books and make books cool again.