This presentation explores thumb-typing as a contemporary cultural technique, investigating how it shapes linguistic and social changes that are part of digital culture. Focusing on human-machine interaction as producing digital textuality, it traces the origins of thumb-typing in the history of typing and the development of digital media. I argue that this history has been characterized by recursive relation between technological infrastructure and typing practices, which has a decisive impact on cultural creation. The analysis shows how the invention of the typewriter keyboard introduced the fingers to typing, and how developments of digital media refined the finger-work in interacting with the device, resulting in thumb-typing. Such shifts not only accompanied the emergence of contemporary digital textuality; they helped producing the very conditions of its existence. Similarly, thumb-typing marks a trajectory towards future textual creativity that is based on collective collaboration between humans and machines.