Yes the Axim has a built-in Compact Flash slot.
And yes, thats the storage card you need.
basically it works like this:
when you install an application to the device, or place a file on the device, it stores it in RAM.
The device allocates 64MB of its built-in RAM to storage as well as program memory (like RAM in a desktop)
Obviously the more things in storage, the less program ram.
So if youve got some larger files you want to have on your PDA, put them on the storage card.
Although I suggest against placing the files onto the card by way of syncing the Axim (putting the card into the Axim then dragging the files into the storage card location) as this will be VERY slow.
Instead, drag yourself onto ebay or even the same place as youre buying the CF card (if you havent already gotten it) and look for a USB card reader that supports Compact Flash.
I myself am a user of Compaq's iPaq 3970 (with built-in Bluetooth). For storage, I use a 256MB Sandisk SD card. My dad has the Axim too, but I think i love my iPaq more 🙂
On the Axim, the SD slot is on the right side. Pop out that little plastic place-holder, THATS HOW BIG SD CARDS ARE. They are the size of a stamp, use a little less power, and have slightly better transfer rates on average.
Compact Flash is better for add-on devices (IBM MicroDrives, modems, Bluetooth adapters, cameras, LAN, etc)
much luck. hope i answered your question?