Google and Sprint announced today that Sprint customers will soon be able to turn their Sprint phone numbers into full-service Google Voice numbers, integrating all the services implied without having to port them or take on a second phone number, as most Google Voice users do. Google and Sprint are consummating this new level of hand-holding with a handset, the Nexus S 4G, which will ship with Android 2.3 Gingerbread on Sprint's network this spring.

With Google Voice integration, Sprint customers will no longer have to activate a second phone number or port their current number, the way Google Voice users currently do. Sprint customers will be able to make their numbers ring on multiple phones by default, and Google Voice's voicemail services will replace the Sprint voicemail interface.

Sprint customers that already have separate Google Voice numbers will be able to adopt them as their primary phone number while retaining all the Voice services. Either way, the integration of Google Voice negates the need for a separate app to use all of the Voice features.

Sprint and Google are dovetailing this announcement with one for the Nexus S 4G, a hotspot-capable Android 2.3 phone that will come with 16GB of internal memory and 512MB RAM. The phone's processor has only a single 1GHz core, which won't make it very competitive among the burgeoning number of dual-core phones, but Samsung has indicated that the phone does have a dedicated GPU.

The launch dates for both Google Voice integration and the Nexus S 4G are vague—Samsung has pegged the Nexus S 4G for "this spring," and Google has said Google Voice integration will be "available soon."