I miss the old, original behavior of ctrl-alt-del, rebooting the system. Once upon a time, kiddies, computers had front panels. Among the buttons on the front panel was a reset button. With the IBM PC and others of its early '80s ilk, the front panel was gone, and often there was no reset button, but there was the three finger salute.
At some point, Windows behavior was to invoke the task manager on a three finger salute rather than to do a system reset. Slackware and other early Linux distros did a reset, which effectively rebooted the system.
Why do I suddenly care? I'm running Ubuntu 9.10 on a 64-bit HP Pavilion desktop. Multiple times per week the system locks up, and ctrl-alt-del does nothing. The GNOME default is log out, but GNOME is locked up at this point. There's a configuration file, /etc/event.d/control-alt-delete, but so far as I can tell the contents of this file are irrelevant and have no effect on system behavior. So my recourse has been to hold the power button down long enough for an abrupt power down. I've been doing this, on average, multiple times per week, when really all I want to do is reboot.
I want my reset button.
Now it turns out that alt-sysreq-b does a reset. Now I just have to remember to try this the next time my system locks up.
Ubuntu: less impressive with every "upgrade."
Hewlett-Packard: less impressive on a year-by-year basis since the merger with Compaq. I guess I could start telling people I'm old enough to remember when HP sold quality products. I worked for a competitor in the telecom instruments segment, and HP was always considered a very worthy competitor. Their laser printers used to be good. Now it's all cheap junk.