After much searching I finally found the software for making the 3com 3c460 usb ethernet boot from the network using PXE, TCPIP, and a few other methods. It's still available from the 3com website at the following url:
There is also a 3rd party company selling(there is a free trial version) the exact same software for any network card imaginable at:
What the software does is create a bootdisk that loads the necessary code to boot from the network. There are a few open source solutions available as well, but I won't mention any of those because as near as I could tell there is no usb support and they have been covered in other posts. I've found a few programs that are capable of creating virtual floppy images that can boot off cd or hard drives, but all of those seem to be proprietary and awkward to implement. Surely there is a simple way to make an image of the boot disk and load that directly onto the flash drive in the I-Opener or maybe from a dos prompt or something? I experimented with creating a disk image with dd in linux and using loadlin unsuccessfully.
The ideal solution would be to have this code load before whatever is on the flash chip in the I-Opener or even before whatever is on your hard drive, I think I'm just missing something very obvious here but I've been staring at the problem too long.
Also, I spent the last several hours searching the forums and archives and to my knowledge nobody has mentioned either of these pieces of software before so I thought it would go well under the breaking news area.