Google will use its surveillance of Web surfing habits to figure out which ads are best suited to each individual's interests. Google seems to capitalize the huge amount of information that has been learning about millions of onlibe users around the world, by making online advertising even more relevant and using additional information about the websites people visit.

This behavioural advertising approach means that someone who frequents sites about dogs might see more ads for flea treatment products even when visiting another Web destination that has nothing to do with pets. Until now, Google has shown ads based mainly on what the users' interests were at a specific moment. So if you search for [digital camera] on Google, you would get ads related to digital cameras.

Google's system initially will work only on its YouTube video sharing site and on websites which use its AdSense technology to choose and display ads. Searches at Google.com will not be affected during the pilot phase.

"We believe there is real value to seeing ads about the things that interest you. If, for example, you love adventure travel and therefore visit adventure travel sites, Google could show you more ads for activities like hiking trips to Patagonia or African safaris. While interest-based advertising can infer your interest in adventure travel from the websites you visit, you can also choose your favorite categories, or tell us which categories you don't want to see ads for," Susan Wojcicki, VP, Product Management of Google explained at the company's blog.

However, behavioural advertising systems have run into controversy over the degree to which people were informed about and able to opt out of the system.

Hoping to avoid a backlash and appease regulators, Google has set up its system so individuals can specify their areas of interest or shun certain forms of advertising at http://www.google.com/ads/preferences.

Google also said that users will have always opt out of the advertising cookie for the AdSense partner network here. To make sure that their opt-out decision is respected (and isn't deleted if a user clear the cookies from his/herbrowser), Google has also designed a plug-in for the browser that maintains users' opt-out choice.

Introduction of Google Voice

In related news, Google also today introduced the Google Voice. The new service weaves traditional phone features with Google's Gmail email product, allowing a person to store transcripts of voicemail phone messages in their email inbox and to find a specific nugget of information within a phone message as if trawling through a sea of emails.

Google Voice offers consumers a single phone number that can route incoming calls to home, office and cell phones. The new version uses speech-recognition technology that Google developed for its Goog-411 telephone directory service, automatically transcribing voicemails into text. The transcribed messages can be forwarded as an email or SMS text message to a person's email inbox.

Google Voice will be available to existing Grand Central users on Thursday and to the general public in the following weeks. GrandCentral service was acquired by Google in July of 2007.

Check out the features page for videos and more information on how these features work.