great BBC radio piece profiling self-initiated mobile library cart operator Martin Murrillo, in Cartegena, Columbia.

“After earning his living as a Cartegena street vendor selling water, Martin decided to not only to teach himself, but to also teach others – especially street children – to read.

“He swapped the water for books that people can borrow from his wooden library cart for free.

“During the week he goes round schools where he talks to the children about the importance of reading and of the books he likes most.”

One of the telling details about Murrillo is that his home is so book-crammed he has to sleep on top of books… like, umm, me.