Feature phones are going the way of the dodo bird in the developed world. But when clamshells and Razors once ruled the earth, shared voice minutes and text eventually became the standard for family mobile plans.

Now that almost everyone and their mothers are carrying around data-sucking smartphones and having to buy data plans for each device, it's time for the wireless carriers to start offering shared data plans. Paying for multiple data plans has become outrageously expensive, especially considering that most of that data is never accessed.

I am not talking about an unlimited data plan. What we need is a way of paying for a specific amount of data shared between all devices on a plan. For example, my wife and I each have an iPhone. We also own a 3G iPad. We pay a combined $80 a month for 2GBs of data on each device per month. We haven't even come close to using 2GBs of data on all of our devices combined since we bought the phones two months ago, and the iPad last summer. Love the devices, hate the waste.

Don't get too excited, but...
It looks like AT&T (NYSE: T) may finally be preparing to set in motion a data-sharing plan. Engadget got a look at what is purported to be a memo to AT&T employees that the carrier's internal system used to manage customer accounts is being updated "in preparation for the launch of Shared Data."

Remember, we've been teased before. Last June, AT&T Mobility CEO Ralph de la Vega told the D9 conference that as people carry more devices, "you may want a shared plan. We're working on one ... It'll be soon. I can't comment on [when] but it will be soon."

And Verizon (NYSE: VZ) CEO Lowell McAdam told a media and communications audience last December, "I think in 2012 we will see it. We have been working on this for a couple of years. Getting to one bill and getting to account-level pricing is our goal."

Yes, I know, Sprint Nextel (NYSE: S) offers what they call an Everything Family Data plan, but I suggest reading the fine print and going through the exercise of setting up a two-line shared data account to check out the final cost before buying into it as a true cost-saving data sharing plan. It's really an "unlimited" data plan with the usual throttling caveats if one uses too much data.

Really, the first one out there with an affordable shared data plan will have a tremendous head start in getting new subscribers and keeping old ones. But, of course, as soon as that first shared plan comes out, it won't be long before the others start offering the same... or better.

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