I have been using a Canon PowerShot G12 for about a year, and find it incredibly slow. In full auto-mode, with good lighting conditions, I feel the G12 regularly takes close to 0.5 s between the time I took a picture and the time I can take the next picture. Compared to the G12, the iPhone 4S and even my ancient Canon EOS 300D feel very snappy.
I suspect the G12 takes all this time to do the focus. In contrast, the iPhone 4S behaves as if it was constantly adjusting the focus to whatever area you clicked on screen, so when the press the "shutter", the picture is also taken instantly, and you can take several pictures in a row without so much lag between them.
Is there a way to achieve a similar result on the G12? Or at least to reduce the delay between the lag between pictures being shot?