i have a cannon and it has options for size and resolution. i set everything at the highest possible(160
1200 and superfine) then i post all my pics on photobucket
and it automatically resizes them for u but only if they are wayyyyy to big. then there is a link right under every picture for posting your pic on this site and it doesnt matter what size or resolution it is. just click on them to see the difference. the second pic is a little blurry but u will almost always start noticing this once u get that big casue of the detail. my camera is only 2mp
this is a 640 x 480 pic on high res
and here is a 1400 x 1000
sorry i am still only freshwater right now but it is a good example as i have very high lighting like salt water.