I am developing a picture site for a blog and am wanting a way to have an image be larger if it is the only image in the post. Currently WordPress will give all my pics a 150px by 150 px thumbnail. I want this 150px thumbnail on most posts except when the post contains only one image. When a post only contains one photo I want the pic to be around 450px wide. Is there any way to configure the site/wordpress to set a condition for such a case as this? Thanks in advance!