Don't bother with Compact Flash cards. You want either Secure Digital or MMC cards. If you see SD or MMC refered to as flash memory, don't let that confuse you. Flash memory is the type of memory that both Compact Flash, Secure Digital and MMC all are. However the only form of flash memory compatible with your axim are the SD and MMC cards.
If you want to listen to music on your PDA, I'd recommend getting a 512 MB SD card at least. If you want to just get started off without too many extras you can try picking up a 128 MB card, they're pretty cheap. Check them out over at ecost.com for some great deals
