Nearly everyone in the world of search is familar with the examples of "miserable failure" and "click here" – two search terms in which the top results don't contain the search terms and rank solely on the strength of external links pointing to them with the corresponding anchor text. But after reviewing some backlinks pointing to Yahoo! today, I noticed quite a few adult-themed domains and a pattern – the anchor text was always the same... "EXIT"

http://www.seomoz.org/blogdetail.php?ID=1440

Pretty cool :) Disney.com/Yahoo.com get a lot of backlinks from adult sites :D

By the way, this is also the explanation for a question that popped up in Chapter 21 (Google Search Tips) of 55 Ways to Have Fun With Google:

[PDF] http://www.55fun.com/book.pdf