First, enter an Apple Store or any other retailer selling iPads, iPhones etc. Pick up an iPad and open the iBooks app. Select Store and search for the particular book – in my case, Remember My Name and Other Stories. Select the book and press Get Sample, and the sample eBook will be downloaded to the device, where it will be available with all the classic (and free) books already there. You can either leave the sample book on screen for the device’s next user or go back to library view.
Now repeat for every iPad/iPhone in the store, or until the staff get wise to what you’re doing and eject you as a sad weirdo.
Sadly, this method will only work on iPads; it won’t work on Kindles as you have to log in with a valid account, not something I’d recommend on a publicly available device.