[font=trebuchet ms]There are a couple of non-factory screw holes in the back of one of my guitars, from my attampts to shift the balance. It didn't work. There's a very good reason for the longer upper horn on a Strat.

What I ended up doing was getting a wide, coarsely-woven cloth strap. Unless I'm wearing a shirt made of something slippery, the friction is usually enough to keep the guitar neck up where it should be. Suede leather would probably work, too, but I wanted something washable. A sweaty leather strap is not a nice thing to have lurking under your nose. And having to hold your guitar up with your fretting hand is not good for your technique![/font]