Paper is not dead

Rule: Post-its will never be obsolete (until digital equivalent is made; really thin, tiny tablets that recognize handwriting... and can stick places?) because writing with one hand is simple. Typing with one hand takes forever. This makes post-its and notepads the number one note-taking thing of choice when people are on the phone (I say this with 0 amount of data and a sample size of me) or just holding something else (hey now) with the other hand.

I realize that this can be solved with headsets, but honestly, not that many people have adopted them, and they are still classified as accessories for a phone. Plus then there's the dichotomy of what if we made all phones headsets vs what if we made all phones tiny tablet computers, etc.

Has anybody come up with a digital equivalent for physical post-it notes that you can quickly jot notes down on while you've got a phone in one hand?

As long as people are trying to note-take with one out of two hands, people will need post-its.