I've noticed on some other vbulletin supported forums that the pictures automatically resize to not expand the window. Its something seperate from what windows IE does sometimes, as I use Opera.
An example is this:
It sizes them down, and then has a clickable part above it to make it full size. Seems like a nice thing to have on here. Not having to scroll back and forth to read stuff because someone posted a big high res picture is nice. Just an idea, not sure if it costs more or is just something you have to turn on.