Don't you hate it when a mega-sized image gets posted and you end up having to scroll side to side to see the complete posts on that page? Well, worry no more. Automatic image resizing software has been added to the site! You can access this feature through your UserCP > Edit Options> Thread Display Options> The Image Resizer.
If you leave the fields blank, all images larger than 400px in width or 600px in height will be resized down to approximately 400px in width or 600px in height.
If you enter a 0 into both fields, then the feature is disabled and you won't see any resizing.
You can also set a custom size if you want to. Just be sure to scroll down and click "Save Changes" if you do anything other than leave the fields blank.