[CentOS] GNOME + Firefox - Mouse froze - what key combination to revive?

Sat Dec 13 18:03:42 UTC 2008
Lanny Marcus <lmmailinglists at gmail.com>

Earlier, I was using GNOME and Firefox and the Mouse died. I had to
kill the power, to get the box going again, because it doesn't have a
reset switch;  which is *not* an elegant way to get going. What key
combination would get me going or to a shell? CentOS 5, fully updated,
32 bit.   TIA!