Get yourself one of
these.
I have tried:
Thisand
thisThey work nicely with 512 MB cards.
The SD adapter was tested with a MMC card.
However
You will need the HDtoolbox from os 3.9...
HDtoolbox from WB3.1 installdisk will provide an "unit is not a disk" error. Had though no problem prepping and formatting using FFS and hdtoolbox from 3.9
If you want a way of transferring data to and from your Amiga.
Get yourself a SCSI controller and a scsi zip for the amiga.
And a IDE zip for your pc.
IMHO it is the best way (without network) to transfer data to and from your amiga