I'm usually editing posts with large images and replacing them with a link to the image instead. Act responsibly and don't flood other members with images.
Actually, I'm hoping Samer will add a script to the forum that automatically resizes large images (perhaps with links to the full size pics), if such a thing is available.
Since the post body is fixed width the image is scaled down automatically. This doesn't solve the image size problem, though.
Proners, no need for a cumbersome tag, just disable images in your profile by unchecking "Show images in posts". I hope this solves your issue. PM me otherwise.