After all, its focus on search is the company’s most powerful weapon against rivals, such as Microsoft and Yahoo, said chief executive Eric Schmidt at the event.

While acknowledging Google’s competitive landscape has become more treacherous in recent years, Schmidt said Google’s key differentiator is its emphasis on search.

The winners will be the fastest innovators who partner most broadly, he said, adding that Google had strong relationships with eBay and AOL.

As Marissa Mayer, VP of Google search products, pointed out, search and its related advertising drives 70% of the company’s business. When it comes to crawling and indexing capabilities, Google has about three times as many pages than any other engine, Mayer said.

However, as the Web grows, each order of magnitude brings new requirements, we need new breakthroughs, new tools to deliver the type of precision you’ve come to know and expect from Google, she said.

Which is why Google announced a slew of new products all based on search.

Firstly, Google Trends, which allows users to search Google traffic for a search term, or combination of search terms. Trends returns data, in graphical form, about the volume of searches for a given term, or terms, as well as the geographic regions in which those searches were conducted.

This may point to when and where a particular term, product or person came into the public’s popular consciousness.

It’s hard to imagine how big this is going to be, said Jonathan Rosenberg, senior VP of Google product management. Imagine if you’re an advertiser and you want to understand trends in different areas or different geographies, or the performance of a[n advertising] campaign in one locale versus another.

To ensure privacy, there is a minimum threshold of volume for a particular search term before it can be used by Trends, he added.

The second new product is called Google Co-op, the basis of which is a recognition that we at Google are not experts on everything, said Mayer.

Google Co-op works like a grocery co-op, she said, except that people contribute labels for links and not vegetables. [Co-op] allow us to build inherent verticals in search, Mayer said.

After all, if a set of URLs had the same label, they are then searchable. For example, if a user searches for malaria, Google Co-op would return sets of labeled searches, such as ‘treatment,’ or ’cause and risk factors.’ Within each group of labels, users would be able to see what each link has been labeled and by whom.

Founding partners of the program, which does not involve a participation fee, include Fandango, Digg News, Gap Minder and OpenTable.com. We will be using it to build more verticals, Mayer said.

The company also launched its latest version 4 of Google Desktop, which features Google Gadgets, a sidebar the company first rolled out in August.

Gadgets now enables users to many numerous interactive applications residing on the sidebar. There also is a recommendation engine built into the Google Desktop, which means users will be advised on what type of gadgets to add to their sidebar, based on their previous Desktop activity. And users can hide or show the sidebar by hitting the ‘shift’ key twice.

Gadgets is only available to users of Google Desktop, Mayer said.

She also noted that Google Desktop can be synced across a users’ multiple PCs. I would call this one of the best applications you may not have installed.

The other new product was Google Notebook. It requires a Google account and a plug-in, and lets users keep a record of recent searches and information from Web sites visited. The notebook also follows users when they leave Google and can be shared with others via e-mail.

Mayer pointed out that all of Google’s new products were centered on search. While it’s easy in the press to get distracted by other announcements … our core and where we innovate most is search, she said.

When asked about monetization of the new products, Mayer said there were no immediate plans to integrate advertising into them. I try to be careful, as does the rest of the management team, to not force monetization on these [products] too early, she said. Advertising follows users.

Clearly, regionalized search is a key area of expansion for Google.

Products no matter where they’re built have to be localized, said Alan Eustace, Google SVP of engineering. Location-specific features would preferably be done as close to a region as possible, although it really depends on what type of feature it is, Eustace said.

Building our international organization is a huge priority for us. All our business teams are very much focused on building that capability across the globe … and being very, very region, said Omid Kordestani, head of Google sales.

When asked about investment in China, in light of eBay last year saying it would spend $100m in the country, Kordestani said Google would take very measured steps. Google would continue to invest in China, but with a very long term view, he said.

APIs for the new Google Desktop and Google Co-op will be made available. Co-founder Sergey Brin later said there were no plans to create a full-fledged application environment for Google, but it could happen.

We come up with new ideas about what could be useful APIs for developers to run on their own and then perhaps have an economic structure around that…there are no plans [for that] today, Brin said.