I have configured my motherboard to S3.
Under XP, Control Panel -> Power Options, set system standby to 1 hr.
under advanced - Set Power buttons to both to stand by.
with S3 (Suspend to RAM), I can wake up the cab in less than 5 seconds.
I have only 1 minor problem with this, my Frontend, which I use MaLa, keyboard does not respond waking up.
If I use use XP, and MAME32, it's fine or anything but MaLa. I guess it's not my XP, keyboard encoder, etc.. I can also use mouse to exit Mala and relaunch..