I saw this picture on Boing Boing. It's a ancient (about 30 years old) hard disk that probably fit about 256K according to a Boing Boing reader.
This iDuck can hold 1000X as much as that disk drive.
And these little 0.2mm RFID chips hold 128K each.
I wonder when they will start selling memory at the drug store in Petabytes per gram...