Just a little suggestion regarding image dimensions.
Is it possible to have a rule applied in the admin panel, so that people cannot upload an image that would display wider than the current board settings - Therefore disalbeling the board to stretch and keeping it verreh sexxeh and schmoooth!
If in any case, the image is too wide, an error message displays denoting that they must upload and place a link in the post?
I think this would keep everything inline and alot neater.
on another forum i go to they have a [screenshot] tag it auto resizes the image but only into 600*480 i think, but there might be an option to change that. . . infact thats probably what your already looking for lol, sorry