When searching for people who linked to Vancouver real estate bloggers in The Tyee (which includes myself), I mistakenly put the URL in the 'blog directory', and not searching blog posts as intended. Instead of results, I was confronted with this error: “There are blogs, and then there's whatever you just typed in. If it's a blog, we don't know about it. Maybe you made a typo. Or maybe it's a blog that doesn't exist. Maybe you don't exist. (In which case, please ignore this.)” [screenshot]
I still don't like Technorati's use of re="nofollow" (especially relevant in the wake of Wikipedia using the 'rel="nofollow"' attribute on all links), but at least they have a sense of humour on their error messages.