Would this problem be my alternator?
 

Hi guys, the other night I was cruising along when my cd-player began to behave erratically and eventually die; during this process, I noticed my hi-beam dropping in intensity 'significantly'. With only 6klms back to my home, I continued along (knowing something electrical has given, or is about to), when the car started losing mechanical power - therefore, I turned the hi-beam to lo-beam (which helped somewhat) when eventually [3klms to go] they also dimmed to near on no existence; therefore, it was time to swap to parkers with engine power still diminishing rapidly. With no more electrical devices consuming power, the only avenue left to save mechanical power was to go down the gears (which got me 300m from my house at a very slow rate) until she couldn't go any further (the car could barely idle at his point, so I switched her off and walked the rest of the way). Does this scenario seem like the alternator has given up [brushes]? Any thoughts and opinions much appreciated. Cheers Peter.

oops, the car is a 93 S coupe, and the battery is next to knew ;)

Good chance it's your alternator. Take the alternator off and take it to Autozone for a free bench test.