well that was my question 2 years ago
the best answer u can get from www.cnet.com

u can find every thing about the camera, and the range of on line price
i bought mine (canon s45....4 migapiexel)
by this way, it was 100$ cheaper than the real price, because of tax
i would suggest canon, it is more easier than nikon, although they said that nikon is the best optics at all(same line as olympus)
i would forget sony
remember, the following things make the difference in prices
1-opticaal zoom, 3 is ok and enough for any one, more than 3 rise price too much
2-resolution, i would not buy less than 2, mine is 4 megapiexel, and 5 is slight better
2-rechargable battary, is very important, digital camera consume battary as crazy machine

do not forget the size, and the outer case
iam very happy with canon, simple and very good resolution
i have sony digital vedio and standstill picture at the same time, but, the standstill is not good

finally, the above mentioned site can give u idea about the camera, and range of prices, but u can fined cheaper on other online shoping web site
best wishess