[Traster]

I think what they were descrbing was more like this: A JPEG uses a Discrete Cosine Transform and then throws away the lower power (higher frequency) values, but does it in a fixed way(blocking). If you re-order the data such that you get all the blocks dc frequency first (rather than all the frequencies for block 0 first) you can stop at any time and you'll have the resolution you "paid" for - ie, your bandwidth is all used for resolution. It's not a bad idea, although I suspect the reason this isn't done is because you don't really need to decided between a 72kb and 73kb image, and in reality there's more to different resolution images than just saving fewere bits (read: interpolation techniques)