Louis, you can increase the compression level of the JPG file without reducing the resolution. Given the grey background, it should compress nicely. I don't know what program you're using, but most allow you to set the compression level as part of the "save" process. Normally you'll see a number (1-12) or words (small size, high quality). Try a mid-range setting, you should be able to get at least 500 pixels across.