Another way to deal with X freezing.

Use acpi to set your power button to switch you to console. Just edit your /etc/acpi/power.sh and change it to...

    #/bin/sh
    /bin/chvt 1

The acpi system is separate from the X/keyboard interface and still works. So this way you can switch to the console even if your keyboard is locked.

Note you can use other keys as well. On my laptop I use my "thinkvantage" key for this. Any key that has an associated acpi event will work.