What is Google Talk?

Google Talk is part-way between a telephone service and a web-based instant messaging service, such as Skype and MSN Messenger. It allows any two people with the right equipment to speak to each other, wherever they are in the world, at no cost.

But it cannot yet replace a conventional telephone. It doesn’t allow you to speak to people who are not Google Talk users, it does not support calls to the emergency services and you can only contact people when they have their PCs switched on.

How do I use it?

The application looks similar to many instant messaging programs. Using the contacts from your Gmail address book (you need to have Gmail to get Google Talk), the system presents you with a list of your friends and indicates whether they are online. To establish a connection you click on the name of the person you wish to call and to end the call you press another button. There is no time limit on calls and no geographical limit on where callers can be, as long as they have an internet connection.

How does it differ from other internet-based telephone services?

In its current incarnation, Google Talk more closely resembles a voice-based instant messaging system than a telephone network. Skype uses similar technology but also allows you to call landlines using a service called Skype Out, which uses the internet to carry the call as far as the local exchange of the person you are calling, and then diverts the call to the standard telephone network (for a fee). Vonage uses the broadband internet network to carry phone calls, but works independently from your computer. You can use your existing phone and make calls to UK and international numbers at reduced rates, but you do have to pay a monthly subscription charge.

What equipment will I need to use Google Talk?

You will need a Windows PC with a speaker and microphone, as well as the Google Talk software, which can be downloaded here. Broadband is recommended, but the service will work with a 56k modem, although the voice quality may be reduced. You also need to be a member of Gmail, Google’s e-mail service, which is currently available by invitation only. Anyone with a Gmail account can invite you to join Gmail and Google Talk, but the company said it does not know when the Gmail service will be made more widely available. It said Google Talk will be adapted for Macintosh and Linux operating systems in the future, although it did not say when.

Is it really free?

There is no charge for the software or for any calls made using the system, so the only expense incurred will be the cost of any new equipment required, such as a microphone and speaker, plus your standard internet connection charges.

Does Google monitor calls?

Google says it will keep a log of connections made using the system, but only to monitor usage and improve the service, and says it does not monitor the content of calls or text-based conversations using the instant messaging service. Mobile phone companies also keep a log of calls made using their networks.

How secure is the service?

Calls made using Google Talk are not encrypted, so there is a risk that they could be intercepted (although calls made using fixed or mobile telephones are also vulnerable to interception). Future versions of the product will support encryption, which will boost security beyond most conventional telephone systems.

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