How can Google be so fast?

What are the technologies and programming decisions that make Google able to serve a query so fast? Every time I search something (one of the several times per day) it always amazes me how they serve the results in near or less than 1 second time. What sort of configuration and algorithms could they have in place that accomplishes this? Side note: It is kind of overwhelming thinking that even if I was to put a desktop application and use it on my machine probably would not be half as fast as Google. Keep on learning I say. Here are some of the great answers and pointers provided: - Google Platform - Map Reduce - Algorithms carefully crafted - Hardware - cluster farms and massive number of cheap computers - Caching and Load Balancing - Google File System