You should be able to setup a usb drive on linux right now (assuming you have hfs support and can format a hfs file system).
What you'll need to do is
1) Partition the usb drive with 1 partition (mbr)
2) Format the partition hfs+
3) Copy all files form the install dvd to the new partition, preserving permissions.
4) Copy the contents of the NetbookCD to the partition
5) Install chameleon onto the usb drive using fdisk and dd.
I haven't done it myself, so you'll have to figure out the commands, but that's essentially how to do it.