External USB-HDD to the PSP ?

[MjN]

Does any1 know if I could somehow connect my 250gb
usb2hdd to my PSP?
I know that it would be possible to connect them by cable,
but then what?

IS there a software which would let me
-open movie/mp3-files from my hdd via my PSP
-open .iso-files directly from my hdd



PS. I only have a 512mb-card.. It´s ok, but still quite small.

[kalle...]

First of all wasn't the psp limited to only ~4gb? Or was that only through the mem stick port, not so sure about the usb port though
EDIT: Plus usb req-s kernel access so i would only work on 1.5/1.0