I've invested in a Canon S1 IS, thanks to the recommendations from the fine folk here. and, I note on some of the review sites that they recommend a high speed Compact Flash card for use with this camera. What cards do you find fast enough? I gather that the speed of the card becomes the limiting factor if you try to do short video clips with this camera. Looks like I can get a 40X or a 66X or an 80X card (all 1 Gb), for incrementally greater money spent. Any comparative experience with cards of these speeds? Thanks.