I just converted the image to indexed mode with the GIMP. The number of colors in the image are potentially reduced, but it often is unnoticeable. The problem with JPEG is that it's a lossy format, so it doesn't hold up well to multiple edits.
Here's a slightly smaller version of the last image, although it still isn't exactly small. [hide][/hide] If I remember, I'll get after this a little more seriously once I get out of class.