I'm a sucker for all kinds of optimization tips, so when I was skimming through my feeds today, Jeff Atwood's post on "Getting the Most Out of PNG" jumped out at me. Jeff points to a great PNG-optimizing utility called PNGOUT, which happens to be written by the guy who wrote the original Duke Nukem 3D rendering engine!

Check out the post for more info. I can confirm that PNGOUT works well, even on images that have already been run through other optimizers.

And while you're at it, you might also want to check out his post on reducing your site's bandwidth usage, which offers some simple and effective tips that I had already been using for a while, but which might be new to some of you.

Good stuff! :)