Good article, screen shots are nice to see too.
TIP: In Photoshop, since the restriction in 600px WIDE, make the photos 600px wide, but 1800px TALL. Add image then crop out whitespace as mentioned. Save the JPG as a JPG file, with a lower quality, like 5. Check the file size to see if the saved file is around 100K. If not, lower the quality and save again. Don't go below 3!