If you are on about connecting this to the Zaurus it will not work.
The SL5500 does not have USB Hosting facilities, you can connect to a USB Host with it (eg your computer) but you can't plug USB accessories into it. The only way around this is if you get a USB Host compact flash card, but these tend to be pricey and generally drain the battery quickly
Your best bet is to keep a look out for a Bluetooth CF card, but make sure it is a compatable one. There are lists on the forums which should tell you what is ok to use.
I managed to pick up one for about £15 inc P+P on ebay, so they do exist