Of course, I'm biased. I wrote the first production version of the system that built the lists of related terms, fine tuned it, and whatnot. It was a pain in the ass for various reasons, but hey, it was innovative, right? :-)
Wow, and all this time later, the Search Easter Egg still lives.
Oh, another interesting tidbit. In roughly 6 months, the core code has gone from Perl to Java and is now C++. Heh.