The first theme is called Silver and it includes custom and random images for the header, custom drop-down menus, author info, two columns, threaded comments, and custom backgrounds.
Paper is the second theme. It’s a bit more simple, as it doesn’t include the large header image that you usually expect from Twenty Eleven.
Download Silver and Paper for free from WP Charity. While you’re there, check out some of their other themes, as a quarter of the price of the themes will be donated to some very good causes around the world.