I have added some comments to my packet driver interface code and created a small sample program to demonstrate how to use it. If you are interested in playing with packet drivers but were daunted by the packet driver specification, this should get you started.
The zip file can be found here: http://brutman.com/Dos_Networking/mTCP.html . Look for 'tcpacket.zip' in the download section.
This should be fairly portable to other versions of C. Also, don't feel that you need to master TCP/IP to use this - you can send *any* packet type you want. Experiment and make your own lightweight protocols!
Mike