[matrss]

Those still have the speed disadvantage of a phone camera and need more space than a compact document scanner, I'd imagine. I guess a ring light for my phone would be an improvement; using the builtin flash usually leads to very uneven lighting in the scan.

[westurner]

IIRC there are certain models of sheet-fed duplex scanners that work with Linux (with e.g. a lower-wattage Pi)