Just a short plea to all WordPress Theme authors.
Please make it easy to find who created a theme.
All you have to do is include the correct information at the top of your CSS.
Here are 2 examples
Theme Name: WordPress Default
Theme URI: http://wordpress.org/
Description: The default WordPress theme based on the famous Kubrick.
Author: Michael Heilemann
Author URI: http://binarybonsai.com/
THEME NAME: blog.txt
THEME URI: http://www.plaintxt.org/themes/blogtxt/
DESCRIPTION: Clean, easy to navigate, and content-centered. Offers a unique CMS-ish home page option. Widgets-friendly and for WordPress 2.0+
AUTHOR: Scott Allan Wallick
AUTHOR URI: http://scottwallick.com/
Now many might regard this as obvious, but some rogue theme authors stick their information in other places, such as in the index.php, or provide no information at all.
This makes it much more time consuming for other people to debug user related problems, and if you want a personal incentive, you get some nice clickable links in the WordPress admin, thus bringing additional traffic.