Hi Nathan,

I've just made an experimental module which offers syscall to privileged
process, which internally translates itself into real sysrq handler
(handle_sysrq) defined in drivers/char/sysrq.c. It occupates itself 
one of unussed linux system calls (concretely stty - no. 31). 
Makefile and patch for that sysrq.c are included in attached archive. 
(I stronly believe i didn't made it reversed :). 
The patch itself only exports 1 variable and 1 function from sysrq.c, 
that normally aren't.

You can make a daemon, which listens on socket and triggers commands
send by clients. Dont call sysrq+boot until a while needed to sync and
unmount. This check, if sync and/or umount were finished before boot,
should be really done, but it would require more changes in kernel
source. And of course, the security is to be taken in client/server
into account.

Bye                                                                   B.