On the eve of Apple's 50th anniversary, I bought an Apple QuickTake 100 from 1994. With help from some passionate indie software developers, I managed to get it up and running.
When you just have to put your signature on a real-life document, but you don't have a standalone scanner handy, the easiest ...
I can tap, scribble, or circle anything on my Android phone to learn more in seconds. It even identifies songs.