Often enough, actually, when I'm driving. My car has a stereo-USB connection that works very well most of the time, allowing me to charge my phone and cycle through my music collection. Its charging speed is slow though, going only at maybe what, 500mA, 1A if I'm lucky? It takes even longer if I'm using Google Maps. To counteract this problem, I've recently started using a power converter, that I normally have for charging my laptop, to charge my phone because it offers a 2.1A USB port that works a LOT better for me.

Why does this matter? Because I can still have my phone's audio going to the car by way of an AUX cable.