Google Voice is coming to Sprint phones — not just smartphones capable of running the Web firm’s call-management software, but even those incapable of Web access. Instead, Sprint will invite subscribers to patch Google’s free service into their current lines.

Under this new option, Sprint customers can either use a Google Voice number in place of their Sprint-assigned digits or they can employ their Sprint number on Google Voice. In both scenarios, as explained in a short YouTube clip, subscribers get all of the usual benefits of Google Voice: automated call screening on a variety of criteria; forwarding to the numbers of your choice at times defined by you; international calling for pennies a minute; and voicemail with automated transcription of callers’ recordings, accessible via the Web.

Google product manager Vincent Paquet said Friday that these features would work across almost all Sprint phones, except for some corporate accounts and pre-paid services like Boost. It’s not reserved for smartphones running Google’s Android operating system, on which Voice isn’t that hard to set up; plain old phones without Web capability can work too because the call forwarding, screening and recording happens outside the phone on Google’s servers and Sprint’s network.

(Sprint’s Android phones already come with a voicemail application that offers a few Google Voice-esque features, such as message transcription at an extra monthly cost; Paquet wasn't sure how that would be replaced or upgraded on a Voice-augmented account.)

This Sprint integration also requires less work than the wireless-number porting that Google introduced in January. But the Overland Park, Kan., carrier’s subscribers will have to wait for it to become available on the Google Voice site, Paquet said Google would need at least two weeks to finish rolling out Voice support.

This could be a big advantage for Sprint, helping to set its service apart from those of larger competitors AT&T and Verizon. Or, at least, it might have before AT&T announced its plans to buy T-Mobile, a move that would cut the number of nationwide wireless carriers from four to three and make this a less competitive market in other, not-as-obvious ways. You tell me: How does the addition of Google Voice change your assessment of Sprint?