Hi,
I just want to introduce Compress-Or-Die which is an online compression tool especially created for the creators of banners... so I hope for the most of you.
It isn't a tool like tinyjpg or jpegmini that just allows to shrink existing JPGs a little bit. It's the one that creates your (also low quality) images from your original data and really squeezes out the last byte. And allows things like JPGs with transparency and "Selective quality" (as known from Adobe Fireworks) btw...
Take a look at it here:
http://compress-or-die.com/
In this context these articles could be interesting that explain a lot of the options you can set:
http://compress-or-die.com/Understanding-JPG
http://compress-or-die.com/Understanding-PNG
I am the author of the tool and the article. So if you have questions, wishes or something else, just drop me a line.
Thanks,
Christoph