Originally Posted by natacha
Once you complete your layout, at the top click on IMAGE then go down to image size, change it to 600x600 pixels, it will look really tiny, don't worry about that. Once you reduce the image size then go to FILE and down to Save for Web, you will then see that the kb's are reduced, I don't know what PSE 3 has but most have where you can decrease the kb's on the right, but usually changing the image size to 600 x600 will get you the right size for posting. Then save it whereever you save your layouts for posting.
Good Luck, Ill be looking for your layout.