Jpeg2000 wavelet compression is the answer here. The more people realise that there are already free browser plugins for viewing jpeg2000 files (the ones with .j2c extension), the quicker the images start to show up in galleries like Rendo's. I have a Morgan plugin in my FireFox and being following the progress of jpeg2000 standardisation for years, I can tell that it easily cuts image sizes to 10%-20% compared to regular jpeg compression without losing image quality. Btw ... quite a few image-editing packages can already write jpeg2000 files - people are just not using them yet. I wish they were.