Ubermensch

This is a very timely post! Just tonight on my way home from work the car was a little difficult to start but the voltage read over 12.5V. During the 15 mile drive home the voltage slowly dropped to just over 10V! I was sweating bullets hoping I would make it home before it died. Now that I'm home I have the battery on a charger but I assume that either my alternator or the voltage regulator is dead. Two questions:

Is there a convenient way to test the voltage regulator functionality?
Has anyone found a convenient source for the regulator? I called a few shops with no luck and the dealerships are closed....

Thanks,

Shawn