@simontatham
Doesn't the Amiga have anything like cat ttyS0 >file? That was my plan for getting files onto a real Amiga, but I haven't gotten around to look up how.
Anyway, there's a bunch of options at http://www.pjhutchison.org/emulation/uae_transfer.html - number 5 (directory) sounds like the easiest. Although that's winuae, so it may have differen features