Just some tips for those using OS X to get the card formatted using a 
CF card reader. I'm using a 400mhz powerbook, OS X.4.1 and a USB 
SanDisk ImageMate 8 in 1 card reader.

I read some of the earlier tips by others regarding getting Monowall 
written to the CF card, but they were not working for me.

Here's what did work...
1) Download the file. Make sure to <ctrl> click the file link and 
select "download linked file". Otherwise Safari was automatically 
decompressing the file causing an issue if I just clicked on the link.

2) find the disk that the card is mounted under. I used disk utility, 
selected the card and clicked on the repair disk option. It outputs a 
message like:
Verifying volume “NO NAME”
** /dev/disk1s1
that's your disk name....

3) now instead of using the unmount or eject button in disk utility, I 
had to use the umount command in terminal.
aaronrobinson$ sudo umount /dev/disk1s1

After doing this, finder will likely complain that the disk was 
improperly unmounted.

If I didn't do this, using Disk utility, I kept getting a message 
saying:  dd: /dev/disk1: Operation not supported.

4) Now, in Terminal write the image to the CF card.
aaronrobinson$ sudo gzcat Desktop/net48xx-1.2b9.img.gz | dd 
of=/dev/disk1 bs=16k

Good luck!
Aaron