Digital notebooks (Electronic Lab Notebooks --- ELNs) exist, but haven't caught on yet. Many researchers often need to be able to note down arbitrary diagrams,

Digital notebooks (Electronic Lab Notebooks --- ELNs) exist, but haven't caught on yet. Many researchers often need to be able to note down arbitrary diagrams, not just text, in real time, which pretty much means low-latency tablet with stylus. This became feasible in just the last decade or so. Many ELNs do implement published hashes for verification ("trusted timestamping").