CF cards are expanding and are cheap:
For example: Magicstor Microdrive by GS Magicstor Inc.
You can never have too much memory for your device. Large GPS maps, music files, movies--all require significant amounts of storage space. This drive delivers lots of storage space and is very reliable. It is available in 2.2 GB and soon 4.2 GB capacities, and requires a Type II CompactFlash slot on your device. The drive spins at 4200 rpm and has an average read-seek time of 10 milliseconds with a data transfer rate of 3.3-6.5 MB/sec. It uses approximately 18 milliamps when idle and 275 milliamps when active. This drive is available now and only a little more expensive than a 1 GB drive. You will wonder how you ever lived without it once you buy it!
Use With: Windows Mobile devices equipped with Type II CF slot
Price: GS1022C-$215.95" [bold added]
You can carry a lot of music on a 4.2GB card
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