It was great when number portability came to cell phones. It was great when Google Voice (nee GrandCentral), promising one number to ring multiple phones emerged as a service. What if you could port your number to Google Voice, though? That’s what TechCrunch says is coming. While the fact that Google Voice is supposed to be a number you can keep forever, if you could port the cell phone number or some business number you have currently plastered all over your business cards to it, think of how much more useful