Haven't make up my mind on these 2 digital cam ... but s1's 10X optical is good lo, pixel is 3.2 whereas Ixus 500 is 5.0. But how many megapix depends on how pic the photo u wan it o be printed. So normally 3.2 will serve the job well. if not wrong Ixus 500 doesn't have any freebies to come along and it cost a bit cheaper than the Canon S1. Image stabelizer is anther good feature for S1. Hmmm, hope to get some advice frm u guys.