We bought this
http://www.testfreaks.com/digitalcameras/samsung-pl55/ for dd last christmas when she was 5. I had read that all the kids cameras had terrible picture quality, and this samsung was shock-proof to 1.2 metres (~4ft), so I figured that dd herself is vary careful, but if she dropped it by accident, or her 3yo brother dropped it (by accident or on purpose) it would survive. All other shock proof models were also water and dust proof and were double the price
It's worked out great - the battery lasts a long time, and we're happy with the quality of pics and video, and dd can use the basic functions, including 'timer' so she can take photos of herself! While it's slightly bulkier than our 3yo pentex optio, it's much more consistent battery-wise, and we almost exclusively use the samsung, except for dh and his iphone. I got it on sale at bestbuy for around $150. (we're in Canada)