I think some of you are underestimating the potential value of a magnetic compass when properly used. If you can't see out the window any more, holding a southerly heading (in the northern hemisphere) may keep your wings attached long enough for you to get to where you can see out again... assuming you don't reach the ground first.
On a southerly heading the compass can help you avoid a spiral dive by indicating turns - even without a gyro. Instead of "Needle, ball, airspeed..." the scan becomes "Compass, yaw string, airspeed..."
The southerly heading is critical as it avoids the northerly turning error and acceleration errors associated with the use of a magnetic compass on other headings.
In the southern hemisphere you head north instead.
Of course, if you have a GPS with a moving map display... and the light is still on... you can do the same thing by keeping the track straight - in any direction (it doesn't have any compass errors).
I consider a compass cheap, reliable insurance. I wouldn't fly without one.
Mike Koerner