Google is asking people to try out its new search infrastructure code-named "Caffeine". Most everybody won't notice a major difference in search results, but just the act of testing Caffeine will help Google engineers speed up and improve search algorithms.
Here's where to find Caffeine: http://www2.sandbox.google.com/
Google says its goal for the new version of Google Search is to improve its indexing speed, accuracy, size, and comprehensiveness.
Read Mashable's detailed analysis of Caffeine's speed, accuracy, temporal relevancy, and index size.
Caffeine: not just for breakfast anymore!