L.D.
My mom send our daughters a Fisher Price camera for Christmas and they love it! It is very durable even for my 2 year old, who already broke my $300 camera twice by just dropping it. It is also extremely easy for them to hold, comes with a case, strap, and USB cord to connect to the computer.
What they like the best is that it works just like a grownup digital - you can zoom and see the pictures right after you take them. Yes, the screen is grainy and the pictures aren't top quality, but they don't seem to care. My 6 year old is just excited to take pictures of her friends at school, soccer, and even of her sisters without Mom hovering over her to make sure the camera isn't messed up.
My advice - get a kid camera for him to practice - taking steady pictures (so they're not blurry), zoom, framing a shot, etc. Then siblings can manhandle it without you having to worry (how crushed would he be if sister broke it?). When he's ready for a more delicate camera you'll know.
Recently I saw the Fisher Price camera at CVS for $29! Good luck!