does it actually save much filesize though?
If those bits are static they wouldn't contribute to the bigness of it?
( Paster of Muppets Join the 39,000 club!, Tue 2 Jan 2007, 19:58, archived)

they're .jpg, so they're smaller files than they would be if just bits of .gif
theoretically
(Sticky Label, Tue 2 Jan 2007, 20:00, archived)