I rarely use a shoulder strap since I usually have a couple of bodies and lenses in a bag. A small wrist strap makes it much more convenient to grab and hold the camera. Here is how I converted my shoulder strap into two free wrist straps.
The wrist strap idea is great if your looking to free up your hands or add a level of security etc. My only concern with that make-up is that it was not designed to be a wrist strap compared to a full neck strap. Good on you for making that though. Great idea.
On a different note, have you ever heard of Black Rapid Straps? They are great straps for holding your camera safely and securely because they are designed for that purpose solely. http://www.blackrapid.com/products
Just some food for thought..