I've put together a couple of quick hacks to let me use usbdm to program hcs08 parts from a linux command-line tool, and to help some with debugging. I've only put in support for the particular hcs08 family I'm using but many of the other devices could be added trivially. In case anyone else out there prefers to work with command-line tools as I do, the source is at:
ftp://ftp.kallisti.com/pub/usbdm_tools/usbdm_tools_v0.1.tar.gz