the second best method:
scanimage | ocr > file
(with 'ocr', of course, aliased to your favorite OCR program)
@typhlosion omg i'm actually sorta into this as like a way of breaking coder's block
@typhlosion we think that there are several actually...
@typhlosion Just cat from the /sys/event/bus/usb wherever your mouse is into a filter that converts it all to ascii printable characters and dump it to a file.
then wag your mouse about and have fun.
the third best would probably be... is there a paint program you can run from the command line that outputs the image you made to stdout after you're done? use that instead of scanimage in the above command and mouse-write your code in