The much-discussed changes to Google's privacy policy are to come into effect tomorrow, meaning the search company will begin collating information on users of sites like Gmail, YouTube, Google Maps and others in order to better understand where those users' interests lie.

At the same time, Google has also condensed and clarified its privacy policy, turfing out the 60 different policies for its various sites and replacing them with one unifying document ‘that's a lot shorter and easier to read'.

Google says the changes are about creating ‘one beautifully simple, intuitive user experience'. For a user looking for an address in Google Maps, for example, if they have previously entered that address into Google Search it will be easier for the text predictor to figure out what the user is looking for.

More important, though, is the ability to target ads more effectively, and thus charge more from advertisers.

Some say this isn't a bad thing – better an appropriate ad than an inappropriate one – but others have called the move another step in the erosion of consumer privacy.

For its part, Google has gone out of its way to make sure the online public are well informed, posting links all over its sites to pages that explain the changes and answer frequently asked questions.

There are guidelines for reducing the amount of data shared under the new scheme, such as switching Gmail chat to ‘off the record', turning on ‘incognito mode' in Chrome, and using Google Dashboard to manage the data that's being made available from each different Google site.

And if you're really not sure, of course there's always the competition.

The new policy applies to all information stored with Google at the time of the switchover and anything collected subsequently, so now's a good time to check out what it's all about and review your own settings.

Image: Google's home page on February 29, commemorating the leap year (frogs) and the birthday of Gioachino Rossini, composer of The Barber of Seville.