Problem Solved!
First, thanks for all the feedback. My problems were as follows:
1. Engine wasn't grounded. (Does that qualify me for the dumbass award?)
2. Alternator was bad.
Luckily the regulator wasn't fried (it's a miracle). The original alternator was purchased from an
Advanced Auto Parts store, so I just explained the situation (they know me by name now, anyway). It was no problem at all. Five minutes later I had a brand new alternator (which they tested before they gave it to me). I took it home, installed it, grounded the motor, and... tada! Everything worked!
Keith