http://www.engadget.com/2007/05/18/siig-rolls-out-usb-to-expresscard-adapter/

Extract from the report -

The only real dig here is that it's only compatible with USB-based ExpressCard devices, meaning PCI-Express based cards won't function via this device.

Can someone please tell me our Sony SXS card that we use on EX1, is it USB-based or PCI-Express based? if it is the former, I would like to buy one and try it on my IBM thinkpad which is without an expresscard slot. Tks

Sorry John,

The EX1 express cards are PCI-express - so this won't work - unfortunately.

Right now this is the only one on the market I see and there are caveats I believe regarding having to reboot on Mac and find hardware device on Windows after each card change.

http://www.synchrotech.com/products-expc/pcie-expresscard-slot-drive_02.html

and they have and explanation of the issue

http://www.synchrotech.com/support/tech-notes-hot_swapping_pcie_based_expresscards.html