Hugh,
Straplocks are the way to go. There are two types: (Schaller) One has a standard post that attaches to the guitar, with a horse-shoe shaped strap attachment that has a spring-loaded pin you pull up on to release the lock. This is the better design. The other (Dunlop?) has a long strap barrel attached to the guitar, and a large capped strap attachment that inserts into the barrel and locks in place when you push down on the button on top. This design has 4 tiny ball bearings that lock in a groove in the barrel, and retract when the top button is depressed releasing the lock. I have had these fail numerous times, and they wear out quickly because the balls are too small. Also, because the lock releases with a push of the button, you can drop your guitar with a misplaced bump! That'll scare your pants off too! Imagine pulling up your guitar and your pants too! You'll miss more than a few beats!
I can also say that any straplock needs to be checked often for loosening hardware: Check the nut on the strap with an adjustable wrench. Leather compresses. Check the screw in the body. Alembics with a mahogany core tend to loosen up on the screws. You can tighten it only so much before you need to add a toothpick. If this works only temporary, you may need to follow the fix in the FAQ section about drilling out the hole, gluing in a hardwood dowel, and redrilling. Sorry, I can't find that post right now, but it it there. I have never had to go this route yet, but it really depends on how much you move around when you play.
Kris