I can't really say that it's
impossible, but I doubt that it would be worth the effort even if it is. I've never seen a device that can host IDE via the CF interface. However, it is possible to use a CF card on an IDE interface with an adapter, like this one:
http://www.magicram.com/IDECompactFlash.htm. If I remember right, it has something to do with the CF design not using all of the IDE commands or something like that.
An easier method would be to get a CompactFlash USB Host card, like the one here:
http://www.ratocsystems.com/english/...ges/cfu1u.html
Once you have that set up you can use any USB Keydrive or portable hard drive with the Axim. Alternatively, you could do what I'm in the process of doing, which is connecting a wireless router with a built-in hard drive for use as a media server for my music. These are also known as "network attached storage" (NAS) devices.