An Abundance of Katherines Resources
Websites

How do your break-ups stack up compared to Colin's? Plug them in to his theorem.

Okay, Sam Ragan isn't particularly relevant, but if you want to play around with anagrams, then this is the site for you.
Articles and Interviews

An interview with author John Green about why and how the wrote the novel.

If you want to know more about why Green chose nineteen girlfriends, or what the deal with tampon strings is, find out in these FAQs about the book.
Video

John Green doesn't just have ideas about math and relationships—he also has something to say about other topics in his video blog.
Audio

An audio version of the book… read by somebody named Kathryn (way to spice up the spelling).