If you're a current subscriber paying $19.99 per month or more with extra lines, you need to call T-Mobile to request the price change, which seems a bit chintzy.

A Wi-Fi radio is also built in, and a $42 per month plan offers unlimited inbound calls over Wi-Fi, with outbound calls for a penny a minute. (There must be additional limits, like landline to cell calling, which is typically ruinously expensive even intra-country; I checked with the firm, and this is the case.) The monthly charge seems a little high, but I'm not aware of any other phone that offers Internet telephony, a roaming handset, and GSM built in. T-Mobile's HotSpot@Home can work over Wi-Fi when you're out of the country, but it's not optimized for that, and I've heard about mixed experiences. T-Mobile also offers the typically high rates for international calling, even when using Wi-Fi to place the outbound call.

The phone works as a mobile callback system, placing the call through their network and then calling you back. There's a delay while calls are connected, Pogue writes, and the quality is similar to that of pure VoIP calls. If you purchase local numbers in cities around the world, people in those cities can call you at no cost, ostensibly. Although I'd like so more details on that: mobile and landline calling is rarely a straightforward billing proposition outside the U.S.

Cubic will sell you the SIM independent of the phone, too. The phone will run $140; the SIM by itself $40. There are no monthly charges.

Update: Pogue found that the calling prices he was quoted were incorrect. There's a long thread about how the company has dealt with pricing, how they were apparently giving Pogue prices in US cents that were in euro cents, and so on.

Femtocells differ from unlicensed mobile access (UMA), in that UMA uses, well, unlicensed 2.4 GHz bandwidth; femtocells using licensed frequencies can push out higher-powered signals and have no competition for the bandwidth. Further, femtocells can work with any existing handset; UMA requires new handsets that combine cell (GSM only at this point) and Wi-Fi or Bluetooth. That's not as big a deal as it used to be, with nearly 100 handsets in production or in the  market that match Wi-Fi with cell.

The service costs $50 for the device and $15 per month for unlimited local and U.S. calling. It's called an Airave, and won't hit nationally until 2008. Femtocells have to account for the part of the country in which they operate as each carrier owns a specific set of spectrum licenses in each geographic area. Any Sprint handset can work with the femtocell.

The cost of femtocells is estimated to be in the hundreds of dollars, making the subsidized $50 price seem rather low. But Alan Nogee of In-State is quoted with an excellent observation in this PC World article: he notes that because most home calling falls into the free weekend/evening minute category anyway, cell carriers aren't making additional revenue. He didn't note, too, that if you have a large minute plan, the carriers would prefer you use fewer minutes until you run over when they'd rather you pay lots of overages.

Thus, any minute pulled from a pool that's then not used or any minute that would have been carried for free as part of a weekend/evening plan that is now part of an additional $15/month in revenue is a savings in cell carriage and an increase in revenue from the monthly fee. I like it. It also keeps people loyal to Sprint.

With UMA, depending on the network, customers can get no-minutes-used calling at hotspots, which isn't an option with femtocells.

I've been dubious about femtocells because their availability is always next year or the year after, no matter how many years back you talk about them. The cost remains high, and it's got a fixed-location utility. T-Mobile can use UMA to give people free calls at 8,500 locations in the U.S. in addition to home. Sprint can give people...better reception at home. So we'll see if the quality issue combined with a Vonage-like pricing plan is enough to get people to give up landlines. Since people still need broadband, which is often coupled or bundled with landline or voice service, there's a question there about whether femtocells are thus compelling enough, too, to replace that.

But Judge notes that while vendors have femtocells on offer, carriers don't have them in live trials yet. At a femtocell conference, he reports on a lot of talk about standards and operator-oriented control tools. There are a lot of issues to be settled, such as will a femtocell allow any user nearby or just the one paying for the broadband? Does their use break ISP agreements on services carried, part of the net neutrality debate?

ABI Research predicted 35m femtocells in use by 2011, but others are dubious, including myself. UMA is a "best-availbility" technology that might wind up being good enough--and which could cost carriers a lot less to rll out to users. Femtocells costs are still quite high compared to comparable Wi-Fi networking equipment, even though femtocells will have lots of advantages for voice users.

Pogue finds the whole package terrific. He's not a big fan of the initial phones or their battery life, but he knows that there will be better phones in the future. He's enthusiastic about the non-zero-sum-game aspect, however, in which both customers and the carrier reduce expenses.