While I was waiting in line to buy some stuff today, the cash register crashed while trying to open the drawer to make change for the person in front of me.  After a few minutes, they decided to reboot the machine, at which point I saw it had 256MB of memory and was running linux (it had the frame-buffer boot screen with the penguin at the top).  The first time it tried to boot, it crashed and rebooted while trying to run fsck.  Strangely, the second time it booted just fine.  The POS software started up exactly where it had died, and kicked out the drawer.

Why does a cash register need 256MB of ram to run a single framebuffer application though?