This is just about the easiest DIY gadget project since the I put an iPad into a Ziploc bag and called it a kitchen-proof case.
It’s called the DIY Camera Wrap Bag, and it is one of the coolest ways to protect your camera whilst making very little effort to do so.
You will need to do some sewing, but you could make a version using gaffer tape and it would work just as well. Take a sheet of suitable fabric (pleather or canvas) and a sheet of felt for the lining. Download Photojojo’s template and cut your sheets to size. Then sew (or tape) them into a bag shape.
This bag, and its wraparound strap. Will cover you camera but let you use the camera’s own straps the shoulder strap. In this way it’s more of a cover than a bag, even though it looks like a stylish bag.
Full instructions can be found at Photojojo, along with that template. I would be tempted if I ever used anything other than the iPhone to take photos these days