So I'm not a kernel programmer, so I may be speaking completely out of 
my ass here, but would it be possible to to strip all of the 
netcard/soundcard/USB/whathaveyou drivers out of the kernel and turn 
them into LKMs? Granted, you'd still want bus and scsi drivers (for boot 
support) in the kernel itself, but what about anything that's not 
required to boot? Perhaps you could even put IPSEC, PPP, and various net 
(anet, pty, gre, etc) stuff in LKMs?

Excuse me if I've just made it painfully obvious that I don't know what 
LKMs are used for. Like I said, I'm not a kernel programmer, just making 
educated guesses.