Some bright folks have dumped and upgraded the firmware for the Canon A570 IS, A610, A620, A630, A640, A700, A710 IS, S2 IS, S3 IS, SD500 and G7. They unlocked raw mode, high speed shutter speeds, live histograms, highlight cropping indicators, and better battery indicators. Quite amazing. If you own one of the above and want to push its limits, check them out at http://chdk.wikia.com/wiki/CHDK