But the lengthy to-do list also includes: making digital copies of all the world's books; establishing electronic file cabinets for people's health records; leading the alternative energy charge away from fossil fuels; selling computer programs to businesses over the Internet; and tweaking its search engine so it can better understand requests stated in plain language, just like a human would.

"There are people who think we are plenty full of ourselves right now, but from inside at least, it doesn't look that way," said Craig Silverstein, Google's technology director and the first employee hired by Page and Brin. "I think what keeps us humble is realizing how much further we have to go."

Page and Brin, both 35 now and worth nearly $19 billion apiece, declined to be interviewed for this story. But they have never left any doubt they view Google as a force for good — a philosophy punctuated by their corporate motto: "Don't Be Evil."

"If we had a lightsaber, we would be Luke (Skywalker)," Silverstein said.

A "Star Wars" analogy can just as easily be used to depict Google as an imposing empire. It holds commanding leads in both the Internet search and advertising markets. The company processes nearly two-thirds of the world's online search requests, according to the research firm comScore Inc., and sells about three-fourths of the ads tied to search requests, according to another firm, eMarketer Inc.

The dominance has enabled Google to rake in $48 billion from Internet ads since 2001. Google hasn't hoarded all of that money: the company has paid $15 billion in commissions to the Web sites that run its ads during the same period, helping to support major online destinations like AOL, Ask.com and MySpace as well as an array of bloggers.

"Google is the oxygen in this ecosystem," Battelle said.

The company hopes to inhale even more Internet advertising from the biggest deal in its short history — a $3.2 billion acquisition of online marketing service DoubleClick Inc. that was completed six months ago.

Google also is trying to mine more money from its second-largest acquisition, YouTube, the Internet's leading video channel. YouTube is expected to generate about $200 million in revenue this year, an amount that analysts believe barely scratches the video site's moneymaking potential.

Eventually, Google Chairman Eric Schmidt wants the entire company to generate $100 billion in annual revenue, which would make it roughly as big as the two largest information-technology companies — Hewlett-Packard Co. and IBM Corp. — each are now. This year, Google will surpass the $20 billion threshold for the first time.