I've just had a good go at sorting out my bike (a Trek 950). During the week I considered replacing it altogether (after the zillionth rear wheel puncture, and the ever-mounting list of stuff that needs sorting), but settled on fixing it up instead. I've just replaced front and back brake and gear cables and all of the brake shoes.
I've done a decent job of it too. I started with a degrease and clean, then replaced the cables and brake shoes. I squirted loads of oil into the cable tubes (shooting 'orrible black gunk out of the other end), and regreased the brake mountings (which looked well beyond due at the back). Finally, re-lubed everything, and even put lacquer on the paintwork that was a bit scratched up.
The associated fiddling that's required when messing with the Chosen Path of gear locations and such like was remarkably easy - it all took about 15 minutes of riding up and down the road with an occasional pit-stop to mess with stuff.
So for the time being, the brakes work far too well, the gears are all aligned and I'm feeling quite smug about the whole thing. Let's see how it goes cycling to and from work/climbing next week...