And once you have resized your images, you can determine the size of the HTML page (that is, in bytes) with HTTP::Size, which will give you an idea of how long it will take to transfer.

Less important these days when even at home most people have 8Mb/sec download rates (at least in this corner of the planet). On the other hand, if absolute numbers of visitors increases, slimmer pages may mean the difference between hitting your monthly cap, or not, if your hoster is that ways inclined.