@monorail I recall my first phone with USB OTG occassionally coming in clutch at school because I could just copy files from and between USB keys and email them
@noiob i had an ipod that i could do that with
you couldn't sync music to it manually, still needed itunes, but it let you look at the filesystem anyway inexplicably. the directory structure was just meaningless. throwing files you needed to bring around later onto the root worked just fine though
it was a pain in the ass but you could do it
@monorail you mean external drive mode? that's a standard iPod feature