In its latest attempt to take over everything Internet, Google has launched an instant messaging (IM) and VoIP (voice over IP) service.

Still in its beta stages, the interface is incredibly simple. No smilies, avatars or file-transfers. All you get is an address book and the option of either a text or voice conversation. When we tested it, voice quality was about average for a VoIP service - calls were pretty clear although not quite as good as the line quality using a BT landline.

Unlike most other popular IM services, including the likes of MSN, Yahoo and AOL, Google Talk uses the open source Jabber protocol to provide its VoIP and IM service. The benefit of this is that it will be able to interoperable with other Jabber-based IM applications.

In order to use Google Talk, you’ll need a Gmail account (also in beta), and the only way to get a Gmail account is to be invited by a current Gmail user.

As it stands, Google Talk has its work cut out with established services, such as Skype and MSN, already boasting huge user bases, and far greater service offerings. Skype, for instance, offers not just PC to PC free calls, but low-cost calls to landlines and mobile phones, a SkypeIn number and voicemail box to receive landline calls, and the ability to make conference calls and IMs. With MSN, you can make free video calls, as wells as free PC to PC calls and instant messaging. 

When both services are fully released, we’ll bring you a more in-depth review, but right now, if you are interested in making free PC to PC calls, we'd advise you to download Skype or MSN instead.

You can download the demo by clicking here.