When I suspend/resume my laptop (A Dell Inspiron E1505 that came pre-installed with Ubuntu,
since upgraded to x86-64 Kubuntu 7.10), about 10% of the time the keyboard and touchpad are
dead when it comes back. The rest of the system is still working fine; if I press the power
button the "log out/suspend/hibernate/restart/turn off" dialog comes up (useless if I have no
mouse and keyboard), and if I plug in a USB mouse or USB keyboard I can use the system
normally. (And if I suspend and resume it again via said USB peripherals, the
keyboard/touchpad controller usually revives itself when it comes back.)
If I don't happen to be carrying USB peripherals around with me, the only thing I can do is
hold the darn power button down until it hard powers off, and then reboot it. I wind up doing
this, on average, about twice a month.
So there _is_ more to life than just trusting your battery...