What a beautifully written hint, one that (in its third step) shows how the late 2008 Macbooks are not as appropriate for wide deployment in an enterprise/institutional environment as the earlier Macbooks.

3A. Remove your battery.
3B. Remove screws (3-4?) and 2.5" SATA Hard Drive.
3C. Place Macbook HD in an external USB / SATA bridge enclosure.
...
5A. Once Disk Utility opens, you will see in the list of drives an external USB drive.
Check to make sure this is the disk you are wanting to use to create a netinstall
image, as it may take some time to create depending on the size of your client machine's drive.

==
Really, it's not that much harder, is it?
Yes, I'd prefer eSATA and FireWire to USB for data transfer as well, but removing the FireWire
from the MacBooks (and Airs, and probably revised Minis) is hardly a dealbreaker
these days with the proliferation of (inexpensive!) USB2 devices.