Things like YSlow and PageSpeed give reports on optimising images but are run manually. YSlow gives a link to smush.it (compress the image via smush.it website - http://smushit.zenfs.com/results/50dfa0f4/smush//theme/4bc93...) which saves 60% and retains it as a PNG.
Personally I couldn't see the image until it was pointed out - so a huge waste of bandwidth for no design gain in my case.
Personally I couldn't see the image until it was pointed out - so a huge waste of bandwidth for no design gain in my case.