For those who don't have access to an optical drive, I've found a guide on how to copy iBoot to a flash drive and make it bootable. This guide, located here:
http://bit.ly/ju5EBp does work as I just finished doing this myself. Unless you are interested in doing this with Windows as well, just follow thru step 12 as this will get the job done for Mac OS X.
I did modify mine a bit and used a 16 Gb flash drive with 3 partitions on it. I set the first one (the iBoot partition) to only 50 Mb as that is all that is needed for those files. I divided the remaining space in 2 equal parts and restored the 10.6.0 retail image to the second partition and the 10.6.3 retail image to the third partition. Now when I boot from this flash drive I can install either one without the need for an optical drive at all.
The guide is a bit cryptic, but it does work if you follow it exactly. I plan to use this on the mini ITX system to give SL one more shot now that I know for sure there is nothing wrong with the ethernet.
Just a message from mosslack...