The GoodThe Sun-Sniper Strap-Surfer lets you use your favorite bag's existing strap.
The BadIt's hard to find a good length for the strap -- long enough to get the camera to your eye but short enough that it doesn't hang too far down. Also, the Strap-Surfer only really works with cameras that have viewfinders, since it's hard to pull it far enough forward to use the LCD.
The Bottom LineIf you want to attach your camera to the outside of an existing bag, the Sun-Sniper Strap-Surfer is a fine option.
If retrieving your camera from a bag is too much work while you're strolling around shooting, Sun-Sniper's Strap-Surfer might be just the ticket.
It's a short strap with a tripod mount that connects to your camera on one end and your bag strap on the other, via an ingenious two-part magnet that interleaves to provide a smoothly sliding attachment. The strap itself is sturdy webbing reinforced with stitched-in steel wire down the center.
This isn't a strap for everyone: it's a nice idea, but can be awkward to use as a full-time strap. I leave it attached to my Shootsac (a lens-only bag) for days when I'm just going out to shoot and won't need to stow the camera at all.