Here's a list of possible solutions. I did not write the list nor needed to try any of the methods listed, so proceed at your own risk:
I received my camera as a Christmas gift in '08 and have had not a single issue with it until last week. My batteries are fully charged and I've even changed the batteries in it, so they are not the issue. I can turn the camera on and look at my pictures, access my menus and everything else. As soon as I hit the button to take a picture, the camera just shuts off. If I turn the camera back on immediately after this happens, the camera comes on but it makes a little clicking noise first. As of right now, my lens is stuck out. Even if I turn the camera on and manually shut it right back off, the lens will not retract. I don't know what is causing this problem and cannot afford repairs or a new camera right now! Any help anyone can give me will be greatly appreciated.