Well, I figured out an easy way to shrink a file for a Mac computer, anyway. If the file is in iPhoto, copy it to the desktop, then control-click and go to Get Info, to see how big the file is to begin with. Mine were about 260-280 KB. Then open the desktop photo by double-clicking on it - it will open in Preview. Click on Tools - Adjust Size... - then I used the percent function to shrink it to about 50%. After saving, I then control-clicked on it again to check Get Info, and they were 48 KB. (You could also crop out unneeded landscape around the subject to get a smaller photo to start with.) And in Adjust Size... there was a function where you could change the resolution, but I didn't have to mess with that. Good luck!