you forget that it checks the sigs during the boot loader portion for the 51d file. so we cant replace it.
Changing the start up sound to flac or something and having a script that does the mounting etc would be a good way i think.
You'd think so, but, it doesn't. (Oops.) The bootloader only checks: hard disk id sector, linux, ramdisk, rc.sh, and phatd.
http://wiki.phathack.com/Bootloader_FAQ51d doesn't get checked until phatd runs; everything from then on seems to use the same bad code that gets fooled by plsign.
I think the easiest way to prepackage a "hack" (at least, in the sense of getting a terminal on the serial port or whatever) is to put out a shell script called 51d, and have it run a hack.sh and then run the real 51d. Sign it, then anyone can download those two files, rename 51d to 51d.real or something, and then copy them to the drive and be off (without having to lose a filetype or whatever).
-b