@Grivusangel -- I've seen those, but didn't know if they worked or not. Good to know they do. I can now save myself a considerable amount of money when I need a car charger.
One of the popular things in my office is the charger that looks like a phone cover, but you put your phone in it and it keeps it charged. I guess that's pretty good, but I have a car charger, and I always plug my phone in every night so it can charge overnight. I rarely go through a full charge in one day. Only if I'm doing a lot of texting, which I rarely do.