similar to lightbox plugin that also fits (shrinks) the image to the screen

I tried with the various li开发者_开发知识库ghtbox plugins for wordpress but they don't resize the image to fit the screen.. is there any that do?

You could try Fancybox. I use it on my own site and it definitely gets the job done. http://wordpress.org/extend/plugins/fancybox-for-wordpress/