This is less a question and more a record of what I've found around the AVCam sample code provided by Apple for iOS4 and 5 camera manipulation. The symptoms of the problem for me were that my app would crash on launching the AVCamViewController after taking around 5-10 photos.

I ran the app through the memory leak profiler and there were no apparent leaks but on inspection with the Activity Monitor I discovered that something called mediaserverd was increasing by 17Mb every time the camera was launched and when it reached ~100Mb the app crashed with multiple low memory warnings.