Google Search (2001), a search interface against a Google index from January, 2001 (FAQ)--and in honor of Google's 10th birthday--is really fascinating.
Doing a search against it for things that are common now--Movable Type, for instance; or, even, blog, which returns only 76,000 results!--yield such different results that it's truly like traveling in time, almost, which, I guess, says something for Google's ubiquity and the expectation--or, at least, my expectation--that search results presented in Google's interface actually reflect the current reality. It's disturbing, slightly.