OK
Had it working for quite a while... but it "broke" when you would edit the post.
I was ready to quit and ask for help.... but then the clouds parted, there was a bright light from above, and I heard harps playing... and I figured it out on my own. Woooo hooo.
I've never screwed around with markup or preg_replace before.... so I was kinda proud that I did it.

Hack is posted
here.It doesn't resize the filesize of the image.. it simply resizes the display of the graphic. So it won't help bandwidth or page load time.... but it will preserve the look of your page if people post HUGE graphics.

Hope it works for you. I could see these "game" sites who want to post lots of screenshots really liking it.
