Gradually, over the past decade, Google has compressed the gap between fresh indexing of the Web from months to mere minutes. On Monday the search giant upped the ante in time-sensitive search, saying that within a few days it will offer search results–including headlines, blogs, tweets, and feeds from Facebook and MySpace–that are just seconds old.

At the same press event, the company unveiled new search features for mobile devices. These include a prototype visual search technology, which allows snapshots of real objects, like signs and buildings, to be used as search “terms.” It also tweaked its geographic search–your GPS-derived position now causes Google to offer different search results based on location. For example: if you start a search with the letters “R” and “E” in Boston, the service will suggest various “Red Sox” search results, while the same two letters typed in San Francisco suggest the retailer REI.

However, Google clearly sees up-to-the-second search results as its most important new offering. The search giant has recently come under unfamiliar pressure from Microsoft’s revamped search engine, Bing, which also provides some “real-time” search results.

“This is the first time, ever, that any search engine has integrated the real-time Web into the results page,” Amit Singhal, a Google fellow, said yesterday in making the announcement.

“Information is being created at a pace I have never seen before–and in this environment, seconds matter,” Singhal added. “I cannot emphasize enough–relevance is the foundation of this product. It is relevance, relevance, relevance. There is so much info being generated out there, getting you relevant information is the key to success of a product like this.”

The arrival of Twitter, in particular, has focused the attention of many Internet companies on the value of real-time information on the Web. By tapping into customers’ interest in time-sensitive information–from Twitter posts to breaking news stories–Google stands to build its audience and, ultimately, its advertising revenues.

The new feature will be available when a user clicks the “Latest results” tab on Google searches. It will be available immediately in English-language countries, but will soon be expanded to other languages, the company says. Searchers will see updates from popular social sites such as Twitter and Friendfeed, and headlines from news sites. Visiting Google Trends and clicking on a “hot topic” will reveal a search results page showing the most popular real-time information.

Other search engines are working to make their results just as fresh. Bing includes some recent results in its search returns, and the newcomer Cuil launched streaming results last month. “It is a good thing to see Google innovate on their search page thanks to competition brought on by other search engines like Bing and Cuil,” said Seval Oz Ozveren, VP for business development at Cuil.

The visual search tool, released in Google Labs, lets users take a photo of a landmark or a store sign, for example, and then searches billions of images for matches, and for Web pages providing relevant information. However, this feature will not include face-recognition software until Google devises a system to protect privacy. “We have decided to delay that until we have more safeguards in place,” says Vic Gundotra, Google’s vice president for engineering.

Dan Weld, a computer scientist and search researcher at the University of Washington, tested the visual search technology and pronounced it “pretty darn cool.” He says that it recognized a can of Diet Dr Pepper and found relevant search returns. And, after initially drawing a blank on a bottle of Lipton Iced Tea, it recognized it with a closer-up shot, and delivered good search results.

Weld suggests that the technology works by doing optical-character recognition of the words, rather than of the labels itself, since at one point it caught the letters “API” from a label and gave him search results for “application programming interface”. The technology also recognized the Seattle space needle and gave him tourist websites. “Not a formal evaluation, but it’s pretty neat,” he says. “And it seems like it has the potential to be a huge opportunity for them if it takes off.”

With the convergence of billions of mobile networked devices, powerful cloud computing resources, and ubiquitous sensors like cameras and GPS chips, “it could be that we are on the cusp of a new computing era,” Gundotra added. “Take the camera and connect it to the cloud, it becomes an eye. The microphone connected to the cloud becomes an ear. Search by site, search by location, search by voice.”