Google has put out a new version of its Google Talk (Gtalk) service for Apple iPhone and iPod Touch users, with design improvements that make the service work solely through Safari, the Apple browser, eliminating the need to download and install any software.

According to a blog post from Google mobile team software engineer Adam Connors, all iPhone and iPod Touch users need to do is log on to www.google.com/talk, sign in, start chatting.

According to Gartner estimates, this year around 2 trillion messages would be sent, and most industry analysts say text messaging will boom even more. However, in parallel, a number of companies are realising that the cellphone has somewhat replaced the computer as an internet connectivity tool, which makes it the ideal medium for chat applications.

Fundamental design changes to the humble mobile phone are now seeing wi-fi, GPRS, 3G and other forms of internet connectivity being built in to handsets, with phones like the iPhone at the head of that change. Already, a small faction of analysts is starting to see a competitor to the hugely popular SMS, or texting service, which has the potential to outstrip the latter in growth.

Again, the fundamental difference between text messages and IM's such as Google's Gtalk is not so much in the using, but in the amount the subscriber pays. While service providers continue to charge per text message, usually of 160 charcters, messages sent via Gtalk on the mobile do not have such character limitation, and are practically free to use, barring the minuscule internet access charge, given the number of messages sent.

AT&T subscribers using the iPhone can do just that, and shave a few dollars off their bill each month, by combining GTalk and the integrated free AOL Instant Messenger client to chat with friends rather than pay for the AT&T SMS plan.

AT&T plans offer iPhone users SMS text messaging plans at $5 for 200 messages a month, or 20 cents per message, $15 for 1,500 messages and $20 for unlimited SMS messages. More IM programs are set to be rolled out in the coming weeks via the iPhone Apps Store, and for now, the Google Talk service through Safari is free.

In his blog post, Connors writes, "We've tried to keep the design as faithful to the desktop experience as possible, so it should be familiar to you. You can select from a quicklist of the people you contact most, search your contacts, and manage multiple conversations."

Users need to keep the service running using Safari. In case they open another application or internet browser, the Google Talk status get changed to "unavailable", until the user reopens Safari. This "unavailable" setting is the only new feature, with the rest of the version's features being identical to the original desktop version.