Google today released Google Talk for Apple iPhone & iPod Touch. You can now stay connected to your friends & family even when you are not using a computer. The Google Talk for iPhone is not a native application but a web version for iPhone.
To use Google Talk on your iPhone simply visit www.google.com/talk in Safari on your phone. You can use Google Talk for iPhone absolutely free of charge. However you may get charged by your operator for data transfer.
Is it one more reason to get an iPhone? Well I am not so sure. If you own some other phone you can check out http://www.google.com/mobile/index.html to see if your phone supports Google Talk.