The WorldWideWeb search engine to end all search engines. Besides the web search, they offer a multide of services:

Google Image Search
Find images by keywords. It doesn't always work well, but it's useful.
The largest UseNet archive around.
Google Directory
A human edited catalogue of web addresses, in cooperation with DMOZ.
Google News

Uses the Google web index to compose information from 4,500 news sources and lets you search the results. can be a good alternative to SlashDot for those not into flamefests. --StuartYeates

A very AJAX-enabled free online e-mail service.
Google Maps
AJAX map service, with street maps and satellite imagery for the US and UK.
An instant messaging network that ties in with GMail.

There also oodles of lesser known services -- see Google Services & Tools. Orkut is a foray of one their employees into the hotbed of online social networks. In anecdotal trivia, Google stated recently that they tested removing their I'm feeling Lucky feature as virtually nobody uses it, but there were howls of protest as it is seen to be part of Google and they recanted.

There are many region specific Google domains like the NewZealand version, which appear to be mainly about selling regoin-specific adds and Sponsored Links. If you're outside NewZealand, it's very likely you found the WlugWiki through Google!

Google was developed at StanfordUniversity, runs on what is probably the world's biggest Linux Cluster (with the exception of storage giant Internet Archive) with near-100% uptime, and currently processes over 200,000,000 queries a day searching a multi-TeraByte index for every query with an average response time of less than a quarter of a second.

They are a great employer, and offer many perks and benefits to their employees. They also demand that each employee spend 20% of their time working on personal projects. In return they are quite demanding and of course they are picky about hirees.

An ex-WaikatoUniversity student (from the Digital Libraries lab) works for Google --