Note that if you already have the Google Talk client installed, you will automatically receive new mail notifications from Google Talk and you do not need to install the Notifier. But unfortunately, no Google Talk for Mac OS X version yet.

[ Download GMail Notifier ]

VoIP is a technology that allows you to make telephone calls using a broadband Internet connection instead of a regular (or analog) phone line. Some services using VoIP may only allow you to call other people using the same service, but others may allow you to call anyone who has a telephone number – including local, long distance, mobile, and international numbers. Also, while some services only work over your computer or a special VoIP phone, other services allow you to use a traditional phone through an adaptor.

A subset of of VoIP services, called PC-to-phone service, is on the rise right now. With these services, users can make calls to and receive calls from regular phones on their PC’s as long they have a broadband connection, VoIP software downloaded from the Web and a headset.

One advantage of such services is the ability to make calls through an Internet-connected laptop when cellular service is unreliable. Many people also prefer the convenience of talking while working on a PC; the services can operate while you are doing other tasks on the computer. Another advantage is price. PC-to-phone VoIP rates are less expensive than conventional phone calls and in many cases cheaper than phone-to-phone VoIP services, which route calls through broadband modems to regular phones.

The first company that offer PC-to-Phone service using VoIP is Skype. Skype gives a (mostly) free VoIP service using file-sharing technology. Now other companies try to follow Skype and get a piece of the VoIP market from them. Yahoo, America Online and Microsoft (who’ve just bought Teleo, a VoIP service company) have each announced plans to add new phone services to future versions of their instant messaging programs. And last week, Google introduced Google Talk, a free service that enables users to talk through their computers and could be a first step toward a PC-to-phone service.

PC-to-phone services available today from companies like Skype, SIPphone, i2Telecom and Dialpad Communications offer many features like free PC-to-PC calling, conference calls, voice mail, choice of phone numbers, call forwarding and reduced long-distance rates, especially for international calls. But as with phone-to-phone VoIP services, call quality is not always perfect.

[ More Information ]

1. Download the theme you want (link above).
2. Go to your Google Talk installation directory (default: C:\Program Files\Google\Google Talk), and rename the application (googletalk.exe) to something else (for example: googlenotalk.exe).
3. Now unzip the theme you just downloaded, and put it into this folder.
4. Run Google Talk and voila!

Screenshot below (source):

[ Via XeroCool ]