First, apologies to Klyphton for borrowing his image without permission.

Best viewed at "Original" size

Can you see the difference between each layer?

The original image was saved with Photo Shop CS using the "Save As" function setting the compression bar from 3 to 11. A slice of each image was then copied into this graphic which was again saved at compression 11. The file size of each saved image is listed belows its slice.

Compression is a function of detail in the image. Little if anything would be gained by getting this image close to 150K

Places to look - check out the boarder between the bright red paint and the background or the subtle orange near the highlight and you can see the image start to breakdown as it gets smaller and smaller.