My girlfriend is getting a smartphone from work, and wanted to get rid of her personal line. She wants to port her personal number to Google Voice, so that she doesn't have to tell everyone her work number. Does anyone have any experience doing this? Will porting automatically cancel that line from AT&T or should she call first? If she ported the number and for whatever reason decided she wanted to use it for a personal line again, could she port that number back back to a carrier? Also, does Google Voice work the same on iPhone? Thanks!