Before the beta version of Google Talk was released, the hype was hot. Was Google going to roll out a killer app and make rival IM clients obsolete? For now at least, the answer is no. Google Talk is as simple as instant messaging gets. The only thing this applet lets you do beyond basic text chatting is wear a headset and speak with friends or colleagues by voice. It lacks many of the bells and whistles of other instant messengers, including emoticons -- those graphical smiley faces that pepper the chat sessions of popular instant-messaging services such as MSN Messenger, Yahoo Messenger, ICQ and Skype.
The 900KB download of Google Talk takes a few seconds via broadband on your Windows 2000 or higher computer. Launch Google Talk, and a clean, unobtrusive floating window appears, instantly adding names from your Gmail address book into your list of contacts. The integration of Gmail and Google Talk will add value for those who already rely heavily on Google's growing service and tools offerings. This window offers just a few links: Inbox, Setting, Help and Add Friend. You also get a search box to look up and invite other Gmail users to chat.
One major benefit to this early version of Google Talk is not so much what it has but rather what it lacks: Google Talk is currently ad-free. Double-click a friend's name, and a small chat window opens, showing only two buttons: Email and Call. Click Email to open a Web browser window and go straight to your Gmail account. Put on a VoIP headset and click Call, and you can talk for free right away to any other Google Talk user. During the conversation, a volume indicator lights up and you can mute the call. We made a call and found the quality to be at least as clear as that of a mobile phone.
Thankfully, in our tests of Google Talk, we didn't run into any operating glitches. The online searchable knowledge base is thorough, if you have questions.

You can use Google Talk only if you use Gmail for email, which until now has been by invitation only. So far, this beta of Google Talk is extremely limited; you can't change your font or background window. And don't even think about viewing the latest news, designing an avatar, linking to friends' blogs or other goodies that Yahoo Messenger with Voice, MSN Messenger 7.0, and Skype offer. Because Google Talk uses the Jabber open-source standard, it works with five lesser-known IM clients, including Trillian Pro, but you'll have to pay Trillian $25 (~£14) for the Pro version. Unfortunately, you can't use Google Talk to chat with people using the popular AIM, MSN Messenger, Yahoo Messenger, ICQ, or Skype. Mac users are also out of luck, although Google says it intends to include them and Linux fans at a later date.
Unlike efforts by IM makers such as Yahoo to filter out uninvited messages from strangers, Google's advice for receiving spam instant messages is simply, 'Ignore them'. Google Talk also lacks the conference calling and encryption-based security features offered through Skype.

Pitted against a deluxe communications suite such as Yahoo Messenger with Voice, the Google Talk beta is the discount motel room of instant messaging. Still, Google will probably add more features and integrate Google Talk into other products. You can already embed this IM client into the new Google Desktop 2.0 sidebar.
Expect all kinds of rumours about Google's next steps. There's already speculation that Google will combine its photo-swapping program Picasa and its Hello chatting tool. Or will Google buy Meetro, a social-networking IM application, so that Google Talk will be able to detect the presence of your friends -- maybe even mapping them via Google Maps? Mere rumours for now. At the moment, Google Talk might be handy for Gmail users, but other IM services with VoIP -- especially Yahoo Messenger with Voice and Skype -- have a lot more to offer.








Talkback
For Linux users Gaim is a good option if you are to use GMail with Jabber.
Google's Talk client is so good *because* it lacks the bells and whistles that the bloated and closed IM clients thrust upon you. Frankly, it's a breath of fresh air.
If you imagine MSN and Yahoo IM's as Altavista when it was at its zenith, imagine Google Talk as what Google was to Altavista at the time.
Clean and simple searching and now clean and simple chatting.
Personally the only addition I would like is something to easily share and edit code with, line by line. That sort of suits the types that use Google.
If they can enable offline messaging on this i think we will have a NEW winner!
IM with voice over www - do you really want it? I make occasional use of an IM client at work. If I need instant answers across sites within the network OK. But PTP messaging with voice over the worldwideswamp? VOIP OK, email almost OK (with SPAM filtering). Am I alone in dreading 'cold messaging' from pushy sales reps.
you can find the same valued info in http://mesengerstalk.com or http://forums.messengerstalk.com