posting photos under100kb without quality loss?

I would just like to know how some of the stunning images on the forum are so high in quality yet under 100kb? Am I doing something wrong. I do a local website photogallery www.ardara.ie/coppermi​ne and have to compress under 100 as well, but the quality is poor. any ideas?

Many members do not attach the photos but host them on either their own website, pbase or other photo hosting site and then link them.

100KB is plenty for good quality web images. Just make sure EXIF, color profile and XMP data are not attached and that you use tools that allow you to control compression level and sharpening for best results. Most use Photoshop and its "Save for Web" command.