SF Chronicle Technology and Business writer Ryan Kim wrote a piece today, “Cutting out the cords,” on the expected transition from landline with/cell phone supplement arrangement, to full reliance on the cell phone; even at home.

By switching to wi-fi networks in their homes, cell phone users will soon be able to ditch their landlines…

Now, I ditched my landline more than two years ago, as I’m sure many others have, especially in Silicon Valley.

But beyond simply getting rid of landlines and phone utility service, Ryan is talking about an expanded function of the cell phone as we know it today.

T-Mobile is testing a dual-mode phone that will allow users to make phone calls from both a cellular network, as well as a wi-fi network. They are expected to conduct a trial run before the end of the year.

Why is this a big deal? The expectation is that the coming dual-mode phones will enable you to take a cellular call, move within range of the wi-fi environment, in your home or elsewhere, and switch to the wi-fi network without the call being effected. And, once you switch to the wi-fi network, that rapid rolling ticker of cellular minutes comes to a stop!

What else?

– Mobile providers will be able to offer customers more services, allowing customers to download big files or receive applications, not currently possible on current devices.

ABI Research reported in September that it expects more than 330 million dual-mode phones will be sold by 2011.

I will welcome this pending personal/professional telecom option that is expected to provide near perfect in-home reception, without relying solely on cellular minute-based plans.