Something borrowed

So This is day 2 of the March Challenge and the topic is "Borrowed". This is Steve's eReader which I have been borrowing for months now, until yesterday when I finally finished "The Post Birthday World" by Lionel Shriver purchased on the Sony eReader. Now I have moved onto my shiny new Amazon kindle touch :)

What has occured to me now though, is how does one "borrow" books on these new e-Readers. I think I still prefer real books but unfortunately I am succumbing to the new devices based on the fact I spend between 2 and 3 hours daily on public transport and they are light, handy and don't take up too much space in the hand bag :)