You can do a lot of cool things with your voice on your phone, but did you know you can make phone calls, too? It's pretty neat. Google Now can even initiate speakerphone calls directly with a voice command.
To make a call on speakerphone, simply say "Call [person] on speakerphone." Google Now will recognise that it should start the call in speakerphone mode. This is particularly handy if you need to make a hands-free call while in the car or when your hands are otherwise occupied. If you haven't already provided it, Google Now may ask for permission to access your device contacts in order to complete this action.