And even though not all current browsers make use of progressive jpeg’s progressive rendering, the ones that do really benefit, and we get file size savings across the board. It’s our best option today and we should use it. Progressive jpegs are the future, not the past.

"The purpose of these color profiles is something I could into another time, but the important thing to remember to avoid problems like Norm's is to make sure all your images were exported in the same way and so they either don't have a color profile or all have the same color profile. This will ensure that the site, at least color-wise, renders the same from browser to browser."